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4049 lines
95 KiB
4049 lines
95 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* Implementation of the security services. |
|
* |
|
* Authors : Stephen Smalley, <[email protected]> |
|
* James Morris <[email protected]> |
|
* |
|
* Updated: Trusted Computer Solutions, Inc. <[email protected]> |
|
* |
|
* Support for enhanced MLS infrastructure. |
|
* Support for context based audit filters. |
|
* |
|
* Updated: Frank Mayer <[email protected]> and Karl MacMillan <[email protected]> |
|
* |
|
* Added conditional policy language extensions |
|
* |
|
* Updated: Hewlett-Packard <[email protected]> |
|
* |
|
* Added support for NetLabel |
|
* Added support for the policy capability bitmap |
|
* |
|
* Updated: Chad Sellers <[email protected]> |
|
* |
|
* Added validation of kernel classes and permissions |
|
* |
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* Updated: KaiGai Kohei <[email protected]> |
|
* |
|
* Added support for bounds domain and audit messaged on masked permissions |
|
* |
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* Updated: Guido Trentalancia <[email protected]> |
|
* |
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* Added support for runtime switching of the policy type |
|
* |
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* Copyright (C) 2008, 2009 NEC Corporation |
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* Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P. |
|
* Copyright (C) 2004-2006 Trusted Computer Solutions, Inc. |
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* Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC |
|
* Copyright (C) 2003 Red Hat, Inc., James Morris <[email protected]> |
|
*/ |
|
#include <linux/kernel.h> |
|
#include <linux/slab.h> |
|
#include <linux/string.h> |
|
#include <linux/spinlock.h> |
|
#include <linux/rcupdate.h> |
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#include <linux/errno.h> |
|
#include <linux/in.h> |
|
#include <linux/sched.h> |
|
#include <linux/audit.h> |
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#include <linux/vmalloc.h> |
|
#include <net/netlabel.h> |
|
|
|
#include "flask.h" |
|
#include "avc.h" |
|
#include "avc_ss.h" |
|
#include "security.h" |
|
#include "context.h" |
|
#include "policydb.h" |
|
#include "sidtab.h" |
|
#include "services.h" |
|
#include "conditional.h" |
|
#include "mls.h" |
|
#include "objsec.h" |
|
#include "netlabel.h" |
|
#include "xfrm.h" |
|
#include "ebitmap.h" |
|
#include "audit.h" |
|
#include "policycap_names.h" |
|
#include "ima.h" |
|
|
|
struct convert_context_args { |
|
struct selinux_state *state; |
|
struct policydb *oldp; |
|
struct policydb *newp; |
|
}; |
|
|
|
struct selinux_policy_convert_data { |
|
struct convert_context_args args; |
|
struct sidtab_convert_params sidtab_params; |
|
}; |
|
|
|
/* Forward declaration. */ |
|
static int context_struct_to_string(struct policydb *policydb, |
|
struct context *context, |
|
char **scontext, |
|
u32 *scontext_len); |
|
|
|
static int sidtab_entry_to_string(struct policydb *policydb, |
|
struct sidtab *sidtab, |
|
struct sidtab_entry *entry, |
|
char **scontext, |
|
u32 *scontext_len); |
|
|
|
static void context_struct_compute_av(struct policydb *policydb, |
|
struct context *scontext, |
|
struct context *tcontext, |
|
u16 tclass, |
|
struct av_decision *avd, |
|
struct extended_perms *xperms); |
|
|
|
static int selinux_set_mapping(struct policydb *pol, |
|
struct security_class_mapping *map, |
|
struct selinux_map *out_map) |
|
{ |
|
u16 i, j; |
|
unsigned k; |
|
bool print_unknown_handle = false; |
|
|
|
/* Find number of classes in the input mapping */ |
|
if (!map) |
|
return -EINVAL; |
|
i = 0; |
|
while (map[i].name) |
|
i++; |
|
|
|
/* Allocate space for the class records, plus one for class zero */ |
|
out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC); |
|
if (!out_map->mapping) |
|
return -ENOMEM; |
|
|
|
/* Store the raw class and permission values */ |
|
j = 0; |
|
while (map[j].name) { |
|
struct security_class_mapping *p_in = map + (j++); |
|
struct selinux_mapping *p_out = out_map->mapping + j; |
|
|
|
/* An empty class string skips ahead */ |
|
if (!strcmp(p_in->name, "")) { |
|
p_out->num_perms = 0; |
|
continue; |
|
} |
|
|
|
p_out->value = string_to_security_class(pol, p_in->name); |
|
if (!p_out->value) { |
|
pr_info("SELinux: Class %s not defined in policy.\n", |
|
p_in->name); |
|
if (pol->reject_unknown) |
|
goto err; |
|
p_out->num_perms = 0; |
|
print_unknown_handle = true; |
|
continue; |
|
} |
|
|
|
k = 0; |
|
while (p_in->perms[k]) { |
|
/* An empty permission string skips ahead */ |
|
if (!*p_in->perms[k]) { |
|
k++; |
|
continue; |
|
} |
|
p_out->perms[k] = string_to_av_perm(pol, p_out->value, |
|
p_in->perms[k]); |
|
if (!p_out->perms[k]) { |
|
pr_info("SELinux: Permission %s in class %s not defined in policy.\n", |
|
p_in->perms[k], p_in->name); |
|
if (pol->reject_unknown) |
|
goto err; |
|
print_unknown_handle = true; |
|
} |
|
|
|
k++; |
|
} |
|
p_out->num_perms = k; |
|
} |
|
|
|
if (print_unknown_handle) |
|
pr_info("SELinux: the above unknown classes and permissions will be %s\n", |
|
pol->allow_unknown ? "allowed" : "denied"); |
|
|
|
out_map->size = i; |
|
return 0; |
|
err: |
|
kfree(out_map->mapping); |
|
out_map->mapping = NULL; |
|
return -EINVAL; |
|
} |
|
|
|
/* |
|
* Get real, policy values from mapped values |
|
*/ |
|
|
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static u16 unmap_class(struct selinux_map *map, u16 tclass) |
|
{ |
|
if (tclass < map->size) |
|
return map->mapping[tclass].value; |
|
|
|
return tclass; |
|
} |
|
|
|
/* |
|
* Get kernel value for class from its policy value |
|
*/ |
|
static u16 map_class(struct selinux_map *map, u16 pol_value) |
|
{ |
|
u16 i; |
|
|
|
for (i = 1; i < map->size; i++) { |
|
if (map->mapping[i].value == pol_value) |
|
return i; |
|
} |
|
|
|
return SECCLASS_NULL; |
|
} |
|
|
|
static void map_decision(struct selinux_map *map, |
|
u16 tclass, struct av_decision *avd, |
|
int allow_unknown) |
|
{ |
|
if (tclass < map->size) { |
|
struct selinux_mapping *mapping = &map->mapping[tclass]; |
|
unsigned int i, n = mapping->num_perms; |
|
u32 result; |
|
|
|
for (i = 0, result = 0; i < n; i++) { |
|
if (avd->allowed & mapping->perms[i]) |
|
result |= 1<<i; |
|
if (allow_unknown && !mapping->perms[i]) |
|
result |= 1<<i; |
|
} |
|
avd->allowed = result; |
|
|
|
for (i = 0, result = 0; i < n; i++) |
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if (avd->auditallow & mapping->perms[i]) |
|
result |= 1<<i; |
|
avd->auditallow = result; |
|
|
|
for (i = 0, result = 0; i < n; i++) { |
|
if (avd->auditdeny & mapping->perms[i]) |
|
result |= 1<<i; |
|
if (!allow_unknown && !mapping->perms[i]) |
|
result |= 1<<i; |
|
} |
|
/* |
|
* In case the kernel has a bug and requests a permission |
|
* between num_perms and the maximum permission number, we |
|
* should audit that denial |
|
*/ |
|
for (; i < (sizeof(u32)*8); i++) |
|
result |= 1<<i; |
|
avd->auditdeny = result; |
|
} |
|
} |
|
|
|
int security_mls_enabled(struct selinux_state *state) |
|
{ |
|
int mls_enabled; |
|
struct selinux_policy *policy; |
|
|
|
if (!selinux_initialized(state)) |
|
return 0; |
|
|
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
mls_enabled = policy->policydb.mls_enabled; |
|
rcu_read_unlock(); |
|
return mls_enabled; |
|
} |
|
|
|
/* |
|
* Return the boolean value of a constraint expression |
|
* when it is applied to the specified source and target |
|
* security contexts. |
|
* |
|
* xcontext is a special beast... It is used by the validatetrans rules |
|
* only. For these rules, scontext is the context before the transition, |
|
* tcontext is the context after the transition, and xcontext is the context |
|
* of the process performing the transition. All other callers of |
|
* constraint_expr_eval should pass in NULL for xcontext. |
|
*/ |
|
static int constraint_expr_eval(struct policydb *policydb, |
|
struct context *scontext, |
|
struct context *tcontext, |
|
struct context *xcontext, |
|
struct constraint_expr *cexpr) |
|
{ |
|
u32 val1, val2; |
|
struct context *c; |
|
struct role_datum *r1, *r2; |
|
struct mls_level *l1, *l2; |
|
struct constraint_expr *e; |
|
int s[CEXPR_MAXDEPTH]; |
|
int sp = -1; |
|
|
|
for (e = cexpr; e; e = e->next) { |
|
switch (e->expr_type) { |
|
case CEXPR_NOT: |
|
BUG_ON(sp < 0); |
|
s[sp] = !s[sp]; |
|
break; |
|
case CEXPR_AND: |
|
BUG_ON(sp < 1); |
|
sp--; |
|
s[sp] &= s[sp + 1]; |
|
break; |
|
case CEXPR_OR: |
|
BUG_ON(sp < 1); |
|
sp--; |
|
s[sp] |= s[sp + 1]; |
|
break; |
|
case CEXPR_ATTR: |
|
if (sp == (CEXPR_MAXDEPTH - 1)) |
|
return 0; |
|
switch (e->attr) { |
|
case CEXPR_USER: |
|
val1 = scontext->user; |
|
val2 = tcontext->user; |
|
break; |
|
case CEXPR_TYPE: |
|
val1 = scontext->type; |
|
val2 = tcontext->type; |
|
break; |
|
case CEXPR_ROLE: |
|
val1 = scontext->role; |
|
val2 = tcontext->role; |
|
r1 = policydb->role_val_to_struct[val1 - 1]; |
|
r2 = policydb->role_val_to_struct[val2 - 1]; |
|
switch (e->op) { |
|
case CEXPR_DOM: |
|
s[++sp] = ebitmap_get_bit(&r1->dominates, |
|
val2 - 1); |
|
continue; |
|
case CEXPR_DOMBY: |
|
s[++sp] = ebitmap_get_bit(&r2->dominates, |
|
val1 - 1); |
|
continue; |
|
case CEXPR_INCOMP: |
|
s[++sp] = (!ebitmap_get_bit(&r1->dominates, |
|
val2 - 1) && |
|
!ebitmap_get_bit(&r2->dominates, |
|
val1 - 1)); |
|
continue; |
|
default: |
|
break; |
|
} |
|
break; |
|
case CEXPR_L1L2: |
|
l1 = &(scontext->range.level[0]); |
|
l2 = &(tcontext->range.level[0]); |
|
goto mls_ops; |
|
case CEXPR_L1H2: |
|
l1 = &(scontext->range.level[0]); |
|
l2 = &(tcontext->range.level[1]); |
|
goto mls_ops; |
|
case CEXPR_H1L2: |
|
l1 = &(scontext->range.level[1]); |
|
l2 = &(tcontext->range.level[0]); |
|
goto mls_ops; |
|
case CEXPR_H1H2: |
|
l1 = &(scontext->range.level[1]); |
|
l2 = &(tcontext->range.level[1]); |
|
goto mls_ops; |
|
case CEXPR_L1H1: |
|
l1 = &(scontext->range.level[0]); |
|
l2 = &(scontext->range.level[1]); |
|
goto mls_ops; |
|
case CEXPR_L2H2: |
|
l1 = &(tcontext->range.level[0]); |
|
l2 = &(tcontext->range.level[1]); |
|
goto mls_ops; |
|
mls_ops: |
|
switch (e->op) { |
|
case CEXPR_EQ: |
|
s[++sp] = mls_level_eq(l1, l2); |
|
continue; |
|
case CEXPR_NEQ: |
|
s[++sp] = !mls_level_eq(l1, l2); |
|
continue; |
|
case CEXPR_DOM: |
|
s[++sp] = mls_level_dom(l1, l2); |
|
continue; |
|
case CEXPR_DOMBY: |
|
s[++sp] = mls_level_dom(l2, l1); |
|
continue; |
|
case CEXPR_INCOMP: |
|
s[++sp] = mls_level_incomp(l2, l1); |
|
continue; |
|
default: |
|
BUG(); |
|
return 0; |
|
} |
|
break; |
|
default: |
|
BUG(); |
|
return 0; |
|
} |
|
|
|
switch (e->op) { |
|
case CEXPR_EQ: |
|
s[++sp] = (val1 == val2); |
|
break; |
|
case CEXPR_NEQ: |
|
s[++sp] = (val1 != val2); |
|
break; |
|
default: |
|
BUG(); |
|
return 0; |
|
} |
|
break; |
|
case CEXPR_NAMES: |
|
if (sp == (CEXPR_MAXDEPTH-1)) |
|
return 0; |
|
c = scontext; |
|
if (e->attr & CEXPR_TARGET) |
|
c = tcontext; |
|
else if (e->attr & CEXPR_XTARGET) { |
|
c = xcontext; |
|
if (!c) { |
|
BUG(); |
|
return 0; |
|
} |
|
} |
|
if (e->attr & CEXPR_USER) |
|
val1 = c->user; |
|
else if (e->attr & CEXPR_ROLE) |
|
val1 = c->role; |
|
else if (e->attr & CEXPR_TYPE) |
|
val1 = c->type; |
|
else { |
|
BUG(); |
|
return 0; |
|
} |
|
|
|
switch (e->op) { |
|
case CEXPR_EQ: |
|
s[++sp] = ebitmap_get_bit(&e->names, val1 - 1); |
|
break; |
|
case CEXPR_NEQ: |
|
s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1); |
|
break; |
|
default: |
|
BUG(); |
|
return 0; |
|
} |
|
break; |
|
default: |
|
BUG(); |
|
return 0; |
|
} |
|
} |
|
|
|
BUG_ON(sp != 0); |
|
return s[0]; |
|
} |
|
|
|
/* |
|
* security_dump_masked_av - dumps masked permissions during |
|
* security_compute_av due to RBAC, MLS/Constraint and Type bounds. |
|
*/ |
|
static int dump_masked_av_helper(void *k, void *d, void *args) |
|
{ |
|
struct perm_datum *pdatum = d; |
|
char **permission_names = args; |
|
|
|
BUG_ON(pdatum->value < 1 || pdatum->value > 32); |
|
|
|
permission_names[pdatum->value - 1] = (char *)k; |
|
|
|
return 0; |
|
} |
|
|
|
static void security_dump_masked_av(struct policydb *policydb, |
|
struct context *scontext, |
|
struct context *tcontext, |
|
u16 tclass, |
|
u32 permissions, |
|
const char *reason) |
|
{ |
|
struct common_datum *common_dat; |
|
struct class_datum *tclass_dat; |
|
struct audit_buffer *ab; |
|
char *tclass_name; |
|
char *scontext_name = NULL; |
|
char *tcontext_name = NULL; |
|
char *permission_names[32]; |
|
int index; |
|
u32 length; |
|
bool need_comma = false; |
|
|
|
if (!permissions) |
|
return; |
|
|
|
tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1); |
|
tclass_dat = policydb->class_val_to_struct[tclass - 1]; |
|
common_dat = tclass_dat->comdatum; |
|
|
|
/* init permission_names */ |
|
if (common_dat && |
|
hashtab_map(&common_dat->permissions.table, |
|
dump_masked_av_helper, permission_names) < 0) |
|
goto out; |
|
|
|
if (hashtab_map(&tclass_dat->permissions.table, |
|
dump_masked_av_helper, permission_names) < 0) |
|
goto out; |
|
|
|
/* get scontext/tcontext in text form */ |
|
if (context_struct_to_string(policydb, scontext, |
|
&scontext_name, &length) < 0) |
|
goto out; |
|
|
|
if (context_struct_to_string(policydb, tcontext, |
|
&tcontext_name, &length) < 0) |
|
goto out; |
|
|
|
/* audit a message */ |
|
ab = audit_log_start(audit_context(), |
|
GFP_ATOMIC, AUDIT_SELINUX_ERR); |
|
if (!ab) |
|
goto out; |
|
|
|
audit_log_format(ab, "op=security_compute_av reason=%s " |
|
"scontext=%s tcontext=%s tclass=%s perms=", |
|
reason, scontext_name, tcontext_name, tclass_name); |
|
|
|
for (index = 0; index < 32; index++) { |
|
u32 mask = (1 << index); |
|
|
|
if ((mask & permissions) == 0) |
|
continue; |
|
|
|
audit_log_format(ab, "%s%s", |
|
need_comma ? "," : "", |
|
permission_names[index] |
|
? permission_names[index] : "????"); |
|
need_comma = true; |
|
} |
|
audit_log_end(ab); |
|
out: |
|
/* release scontext/tcontext */ |
|
kfree(tcontext_name); |
|
kfree(scontext_name); |
|
|
|
return; |
|
} |
|
|
|
/* |
|
* security_boundary_permission - drops violated permissions |
|
* on boundary constraint. |
|
*/ |
|
static void type_attribute_bounds_av(struct policydb *policydb, |
|
struct context *scontext, |
|
struct context *tcontext, |
|
u16 tclass, |
|
struct av_decision *avd) |
|
{ |
|
struct context lo_scontext; |
|
struct context lo_tcontext, *tcontextp = tcontext; |
|
struct av_decision lo_avd; |
|
struct type_datum *source; |
|
struct type_datum *target; |
|
u32 masked = 0; |
|
|
|
source = policydb->type_val_to_struct[scontext->type - 1]; |
|
BUG_ON(!source); |
|
|
|
if (!source->bounds) |
|
return; |
|
|
|
target = policydb->type_val_to_struct[tcontext->type - 1]; |
|
BUG_ON(!target); |
|
|
|
memset(&lo_avd, 0, sizeof(lo_avd)); |
|
|
|
memcpy(&lo_scontext, scontext, sizeof(lo_scontext)); |
|
lo_scontext.type = source->bounds; |
|
|
|
if (target->bounds) { |
|
memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext)); |
|
lo_tcontext.type = target->bounds; |
|
tcontextp = &lo_tcontext; |
|
} |
|
|
|
context_struct_compute_av(policydb, &lo_scontext, |
|
tcontextp, |
|
tclass, |
|
&lo_avd, |
|
NULL); |
|
|
|
masked = ~lo_avd.allowed & avd->allowed; |
|
|
|
if (likely(!masked)) |
|
return; /* no masked permission */ |
|
|
|
/* mask violated permissions */ |
|
avd->allowed &= ~masked; |
|
|
|
/* audit masked permissions */ |
|
security_dump_masked_av(policydb, scontext, tcontext, |
|
tclass, masked, "bounds"); |
|
} |
|
|
|
/* |
|
* flag which drivers have permissions |
|
* only looking for ioctl based extended permssions |
|
*/ |
|
void services_compute_xperms_drivers( |
|
struct extended_perms *xperms, |
|
struct avtab_node *node) |
|
{ |
|
unsigned int i; |
|
|
|
if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { |
|
/* if one or more driver has all permissions allowed */ |
|
for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++) |
|
xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i]; |
|
} else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { |
|
/* if allowing permissions within a driver */ |
|
security_xperm_set(xperms->drivers.p, |
|
node->datum.u.xperms->driver); |
|
} |
|
|
|
xperms->len = 1; |
|
} |
|
|
|
/* |
|
* Compute access vectors and extended permissions based on a context |
|
* structure pair for the permissions in a particular class. |
|
*/ |
|
static void context_struct_compute_av(struct policydb *policydb, |
|
struct context *scontext, |
|
struct context *tcontext, |
|
u16 tclass, |
|
struct av_decision *avd, |
|
struct extended_perms *xperms) |
|
{ |
|
struct constraint_node *constraint; |
|
struct role_allow *ra; |
|
struct avtab_key avkey; |
|
struct avtab_node *node; |
|
struct class_datum *tclass_datum; |
|
struct ebitmap *sattr, *tattr; |
|
struct ebitmap_node *snode, *tnode; |
|
unsigned int i, j; |
|
|
|
avd->allowed = 0; |
|
avd->auditallow = 0; |
|
avd->auditdeny = 0xffffffff; |
|
if (xperms) { |
|
memset(&xperms->drivers, 0, sizeof(xperms->drivers)); |
|
xperms->len = 0; |
|
} |
|
|
|
if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { |
|
if (printk_ratelimit()) |
|
pr_warn("SELinux: Invalid class %hu\n", tclass); |
|
return; |
|
} |
|
|
|
tclass_datum = policydb->class_val_to_struct[tclass - 1]; |
|
|
|
/* |
|
* If a specific type enforcement rule was defined for |
|
* this permission check, then use it. |
|
*/ |
|
avkey.target_class = tclass; |
|
avkey.specified = AVTAB_AV | AVTAB_XPERMS; |
|
sattr = &policydb->type_attr_map_array[scontext->type - 1]; |
|
tattr = &policydb->type_attr_map_array[tcontext->type - 1]; |
|
ebitmap_for_each_positive_bit(sattr, snode, i) { |
|
ebitmap_for_each_positive_bit(tattr, tnode, j) { |
|
avkey.source_type = i + 1; |
|
avkey.target_type = j + 1; |
|
for (node = avtab_search_node(&policydb->te_avtab, |
|
&avkey); |
|
node; |
|
node = avtab_search_node_next(node, avkey.specified)) { |
|
if (node->key.specified == AVTAB_ALLOWED) |
|
avd->allowed |= node->datum.u.data; |
|
else if (node->key.specified == AVTAB_AUDITALLOW) |
|
avd->auditallow |= node->datum.u.data; |
|
else if (node->key.specified == AVTAB_AUDITDENY) |
|
avd->auditdeny &= node->datum.u.data; |
|
else if (xperms && (node->key.specified & AVTAB_XPERMS)) |
|
services_compute_xperms_drivers(xperms, node); |
|
} |
|
|
|
/* Check conditional av table for additional permissions */ |
|
cond_compute_av(&policydb->te_cond_avtab, &avkey, |
|
avd, xperms); |
|
|
|
} |
|
} |
|
|
|
/* |
|
* Remove any permissions prohibited by a constraint (this includes |
|
* the MLS policy). |
|
*/ |
|
constraint = tclass_datum->constraints; |
|
while (constraint) { |
|
if ((constraint->permissions & (avd->allowed)) && |
|
!constraint_expr_eval(policydb, scontext, tcontext, NULL, |
|
constraint->expr)) { |
|
avd->allowed &= ~(constraint->permissions); |
|
} |
|
constraint = constraint->next; |
|
} |
|
|
|
/* |
|
* If checking process transition permission and the |
|
* role is changing, then check the (current_role, new_role) |
|
* pair. |
|
*/ |
|
if (tclass == policydb->process_class && |
|
(avd->allowed & policydb->process_trans_perms) && |
|
scontext->role != tcontext->role) { |
|
for (ra = policydb->role_allow; ra; ra = ra->next) { |
|
if (scontext->role == ra->role && |
|
tcontext->role == ra->new_role) |
|
break; |
|
} |
|
if (!ra) |
|
avd->allowed &= ~policydb->process_trans_perms; |
|
} |
|
|
|
/* |
|
* If the given source and target types have boundary |
|
* constraint, lazy checks have to mask any violated |
|
* permission and notice it to userspace via audit. |
|
*/ |
|
type_attribute_bounds_av(policydb, scontext, tcontext, |
|
tclass, avd); |
|
} |
|
|
|
static int security_validtrans_handle_fail(struct selinux_state *state, |
|
struct selinux_policy *policy, |
|
struct sidtab_entry *oentry, |
|
struct sidtab_entry *nentry, |
|
struct sidtab_entry *tentry, |
|
u16 tclass) |
|
{ |
|
struct policydb *p = &policy->policydb; |
|
struct sidtab *sidtab = policy->sidtab; |
|
char *o = NULL, *n = NULL, *t = NULL; |
|
u32 olen, nlen, tlen; |
|
|
|
if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen)) |
|
goto out; |
|
if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen)) |
|
goto out; |
|
if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen)) |
|
goto out; |
|
audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR, |
|
"op=security_validate_transition seresult=denied" |
|
" oldcontext=%s newcontext=%s taskcontext=%s tclass=%s", |
|
o, n, t, sym_name(p, SYM_CLASSES, tclass-1)); |
|
out: |
|
kfree(o); |
|
kfree(n); |
|
kfree(t); |
|
|
|
if (!enforcing_enabled(state)) |
|
return 0; |
|
return -EPERM; |
|
} |
|
|
|
static int security_compute_validatetrans(struct selinux_state *state, |
|
u32 oldsid, u32 newsid, u32 tasksid, |
|
u16 orig_tclass, bool user) |
|
{ |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
struct sidtab *sidtab; |
|
struct sidtab_entry *oentry; |
|
struct sidtab_entry *nentry; |
|
struct sidtab_entry *tentry; |
|
struct class_datum *tclass_datum; |
|
struct constraint_node *constraint; |
|
u16 tclass; |
|
int rc = 0; |
|
|
|
|
|
if (!selinux_initialized(state)) |
|
return 0; |
|
|
|
rcu_read_lock(); |
|
|
|
policy = rcu_dereference(state->policy); |
|
policydb = &policy->policydb; |
|
sidtab = policy->sidtab; |
|
|
|
if (!user) |
|
tclass = unmap_class(&policy->map, orig_tclass); |
|
else |
|
tclass = orig_tclass; |
|
|
|
if (!tclass || tclass > policydb->p_classes.nprim) { |
|
rc = -EINVAL; |
|
goto out; |
|
} |
|
tclass_datum = policydb->class_val_to_struct[tclass - 1]; |
|
|
|
oentry = sidtab_search_entry(sidtab, oldsid); |
|
if (!oentry) { |
|
pr_err("SELinux: %s: unrecognized SID %d\n", |
|
__func__, oldsid); |
|
rc = -EINVAL; |
|
goto out; |
|
} |
|
|
|
nentry = sidtab_search_entry(sidtab, newsid); |
|
if (!nentry) { |
|
pr_err("SELinux: %s: unrecognized SID %d\n", |
|
__func__, newsid); |
|
rc = -EINVAL; |
|
goto out; |
|
} |
|
|
|
tentry = sidtab_search_entry(sidtab, tasksid); |
|
if (!tentry) { |
|
pr_err("SELinux: %s: unrecognized SID %d\n", |
|
__func__, tasksid); |
|
rc = -EINVAL; |
|
goto out; |
|
} |
|
|
|
constraint = tclass_datum->validatetrans; |
|
while (constraint) { |
|
if (!constraint_expr_eval(policydb, &oentry->context, |
|
&nentry->context, &tentry->context, |
|
constraint->expr)) { |
|
if (user) |
|
rc = -EPERM; |
|
else |
|
rc = security_validtrans_handle_fail(state, |
|
policy, |
|
oentry, |
|
nentry, |
|
tentry, |
|
tclass); |
|
goto out; |
|
} |
|
constraint = constraint->next; |
|
} |
|
|
|
out: |
|
rcu_read_unlock(); |
|
return rc; |
|
} |
|
|
|
int security_validate_transition_user(struct selinux_state *state, |
|
u32 oldsid, u32 newsid, u32 tasksid, |
|
u16 tclass) |
|
{ |
|
return security_compute_validatetrans(state, oldsid, newsid, tasksid, |
|
tclass, true); |
|
} |
|
|
|
int security_validate_transition(struct selinux_state *state, |
|
u32 oldsid, u32 newsid, u32 tasksid, |
|
u16 orig_tclass) |
|
{ |
|
return security_compute_validatetrans(state, oldsid, newsid, tasksid, |
|
orig_tclass, false); |
|
} |
|
|
|
/* |
|
* security_bounded_transition - check whether the given |
|
* transition is directed to bounded, or not. |
|
* It returns 0, if @newsid is bounded by @oldsid. |
|
* Otherwise, it returns error code. |
|
* |
|
* @oldsid : current security identifier |
|
* @newsid : destinated security identifier |
|
*/ |
|
int security_bounded_transition(struct selinux_state *state, |
|
u32 old_sid, u32 new_sid) |
|
{ |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
struct sidtab *sidtab; |
|
struct sidtab_entry *old_entry, *new_entry; |
|
struct type_datum *type; |
|
int index; |
|
int rc; |
|
|
|
if (!selinux_initialized(state)) |
|
return 0; |
|
|
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
policydb = &policy->policydb; |
|
sidtab = policy->sidtab; |
|
|
|
rc = -EINVAL; |
|
old_entry = sidtab_search_entry(sidtab, old_sid); |
|
if (!old_entry) { |
|
pr_err("SELinux: %s: unrecognized SID %u\n", |
|
__func__, old_sid); |
|
goto out; |
|
} |
|
|
|
rc = -EINVAL; |
|
new_entry = sidtab_search_entry(sidtab, new_sid); |
|
if (!new_entry) { |
|
pr_err("SELinux: %s: unrecognized SID %u\n", |
|
__func__, new_sid); |
|
goto out; |
|
} |
|
|
|
rc = 0; |
|
/* type/domain unchanged */ |
|
if (old_entry->context.type == new_entry->context.type) |
|
goto out; |
|
|
|
index = new_entry->context.type; |
|
while (true) { |
|
type = policydb->type_val_to_struct[index - 1]; |
|
BUG_ON(!type); |
|
|
|
/* not bounded anymore */ |
|
rc = -EPERM; |
|
if (!type->bounds) |
|
break; |
|
|
|
/* @newsid is bounded by @oldsid */ |
|
rc = 0; |
|
if (type->bounds == old_entry->context.type) |
|
break; |
|
|
|
index = type->bounds; |
|
} |
|
|
|
if (rc) { |
|
char *old_name = NULL; |
|
char *new_name = NULL; |
|
u32 length; |
|
|
|
if (!sidtab_entry_to_string(policydb, sidtab, old_entry, |
|
&old_name, &length) && |
|
!sidtab_entry_to_string(policydb, sidtab, new_entry, |
|
&new_name, &length)) { |
|
audit_log(audit_context(), |
|
GFP_ATOMIC, AUDIT_SELINUX_ERR, |
|
"op=security_bounded_transition " |
|
"seresult=denied " |
|
"oldcontext=%s newcontext=%s", |
|
old_name, new_name); |
|
} |
|
kfree(new_name); |
|
kfree(old_name); |
|
} |
|
out: |
|
rcu_read_unlock(); |
|
|
|
return rc; |
|
} |
|
|
|
static void avd_init(struct selinux_policy *policy, struct av_decision *avd) |
|
{ |
|
avd->allowed = 0; |
|
avd->auditallow = 0; |
|
avd->auditdeny = 0xffffffff; |
|
if (policy) |
|
avd->seqno = policy->latest_granting; |
|
else |
|
avd->seqno = 0; |
|
avd->flags = 0; |
|
} |
|
|
|
void services_compute_xperms_decision(struct extended_perms_decision *xpermd, |
|
struct avtab_node *node) |
|
{ |
|
unsigned int i; |
|
|
|
if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { |
|
if (xpermd->driver != node->datum.u.xperms->driver) |
|
return; |
|
} else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { |
|
if (!security_xperm_test(node->datum.u.xperms->perms.p, |
|
xpermd->driver)) |
|
return; |
|
} else { |
|
BUG(); |
|
} |
|
|
|
if (node->key.specified == AVTAB_XPERMS_ALLOWED) { |
|
xpermd->used |= XPERMS_ALLOWED; |
|
if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { |
|
memset(xpermd->allowed->p, 0xff, |
|
sizeof(xpermd->allowed->p)); |
|
} |
|
if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { |
|
for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++) |
|
xpermd->allowed->p[i] |= |
|
node->datum.u.xperms->perms.p[i]; |
|
} |
|
} else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) { |
|
xpermd->used |= XPERMS_AUDITALLOW; |
|
if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { |
|
memset(xpermd->auditallow->p, 0xff, |
|
sizeof(xpermd->auditallow->p)); |
|
} |
|
if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { |
|
for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++) |
|
xpermd->auditallow->p[i] |= |
|
node->datum.u.xperms->perms.p[i]; |
|
} |
|
} else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) { |
|
xpermd->used |= XPERMS_DONTAUDIT; |
|
if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { |
|
memset(xpermd->dontaudit->p, 0xff, |
|
sizeof(xpermd->dontaudit->p)); |
|
} |
|
if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { |
|
for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++) |
|
xpermd->dontaudit->p[i] |= |
|
node->datum.u.xperms->perms.p[i]; |
|
} |
|
} else { |
|
BUG(); |
|
} |
|
} |
|
|
|
void security_compute_xperms_decision(struct selinux_state *state, |
|
u32 ssid, |
|
u32 tsid, |
|
u16 orig_tclass, |
|
u8 driver, |
|
struct extended_perms_decision *xpermd) |
|
{ |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
struct sidtab *sidtab; |
|
u16 tclass; |
|
struct context *scontext, *tcontext; |
|
struct avtab_key avkey; |
|
struct avtab_node *node; |
|
struct ebitmap *sattr, *tattr; |
|
struct ebitmap_node *snode, *tnode; |
|
unsigned int i, j; |
|
|
|
xpermd->driver = driver; |
|
xpermd->used = 0; |
|
memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p)); |
|
memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p)); |
|
memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p)); |
|
|
|
rcu_read_lock(); |
|
if (!selinux_initialized(state)) |
|
goto allow; |
|
|
|
policy = rcu_dereference(state->policy); |
|
policydb = &policy->policydb; |
|
sidtab = policy->sidtab; |
|
|
|
scontext = sidtab_search(sidtab, ssid); |
|
if (!scontext) { |
|
pr_err("SELinux: %s: unrecognized SID %d\n", |
|
__func__, ssid); |
|
goto out; |
|
} |
|
|
|
tcontext = sidtab_search(sidtab, tsid); |
|
if (!tcontext) { |
|
pr_err("SELinux: %s: unrecognized SID %d\n", |
|
__func__, tsid); |
|
goto out; |
|
} |
|
|
|
tclass = unmap_class(&policy->map, orig_tclass); |
|
if (unlikely(orig_tclass && !tclass)) { |
|
if (policydb->allow_unknown) |
|
goto allow; |
|
goto out; |
|
} |
|
|
|
|
|
if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { |
|
pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass); |
|
goto out; |
|
} |
|
|
|
avkey.target_class = tclass; |
|
avkey.specified = AVTAB_XPERMS; |
|
sattr = &policydb->type_attr_map_array[scontext->type - 1]; |
|
tattr = &policydb->type_attr_map_array[tcontext->type - 1]; |
|
ebitmap_for_each_positive_bit(sattr, snode, i) { |
|
ebitmap_for_each_positive_bit(tattr, tnode, j) { |
|
avkey.source_type = i + 1; |
|
avkey.target_type = j + 1; |
|
for (node = avtab_search_node(&policydb->te_avtab, |
|
&avkey); |
|
node; |
|
node = avtab_search_node_next(node, avkey.specified)) |
|
services_compute_xperms_decision(xpermd, node); |
|
|
|
cond_compute_xperms(&policydb->te_cond_avtab, |
|
&avkey, xpermd); |
|
} |
|
} |
|
out: |
|
rcu_read_unlock(); |
|
return; |
|
allow: |
|
memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p)); |
|
goto out; |
|
} |
|
|
|
/** |
|
* security_compute_av - Compute access vector decisions. |
|
* @ssid: source security identifier |
|
* @tsid: target security identifier |
|
* @tclass: target security class |
|
* @avd: access vector decisions |
|
* @xperms: extended permissions |
|
* |
|
* Compute a set of access vector decisions based on the |
|
* SID pair (@ssid, @tsid) for the permissions in @tclass. |
|
*/ |
|
void security_compute_av(struct selinux_state *state, |
|
u32 ssid, |
|
u32 tsid, |
|
u16 orig_tclass, |
|
struct av_decision *avd, |
|
struct extended_perms *xperms) |
|
{ |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
struct sidtab *sidtab; |
|
u16 tclass; |
|
struct context *scontext = NULL, *tcontext = NULL; |
|
|
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
avd_init(policy, avd); |
|
xperms->len = 0; |
|
if (!selinux_initialized(state)) |
|
goto allow; |
|
|
|
policydb = &policy->policydb; |
|
sidtab = policy->sidtab; |
|
|
|
scontext = sidtab_search(sidtab, ssid); |
|
if (!scontext) { |
|
pr_err("SELinux: %s: unrecognized SID %d\n", |
|
__func__, ssid); |
|
goto out; |
|
} |
|
|
|
/* permissive domain? */ |
|
if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) |
|
avd->flags |= AVD_FLAGS_PERMISSIVE; |
|
|
|
tcontext = sidtab_search(sidtab, tsid); |
|
if (!tcontext) { |
|
pr_err("SELinux: %s: unrecognized SID %d\n", |
|
__func__, tsid); |
|
goto out; |
|
} |
|
|
|
tclass = unmap_class(&policy->map, orig_tclass); |
|
if (unlikely(orig_tclass && !tclass)) { |
|
if (policydb->allow_unknown) |
|
goto allow; |
|
goto out; |
|
} |
|
context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, |
|
xperms); |
|
map_decision(&policy->map, orig_tclass, avd, |
|
policydb->allow_unknown); |
|
out: |
|
rcu_read_unlock(); |
|
return; |
|
allow: |
|
avd->allowed = 0xffffffff; |
|
goto out; |
|
} |
|
|
|
void security_compute_av_user(struct selinux_state *state, |
|
u32 ssid, |
|
u32 tsid, |
|
u16 tclass, |
|
struct av_decision *avd) |
|
{ |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
struct sidtab *sidtab; |
|
struct context *scontext = NULL, *tcontext = NULL; |
|
|
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
avd_init(policy, avd); |
|
if (!selinux_initialized(state)) |
|
goto allow; |
|
|
|
policydb = &policy->policydb; |
|
sidtab = policy->sidtab; |
|
|
|
scontext = sidtab_search(sidtab, ssid); |
|
if (!scontext) { |
|
pr_err("SELinux: %s: unrecognized SID %d\n", |
|
__func__, ssid); |
|
goto out; |
|
} |
|
|
|
/* permissive domain? */ |
|
if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) |
|
avd->flags |= AVD_FLAGS_PERMISSIVE; |
|
|
|
tcontext = sidtab_search(sidtab, tsid); |
|
if (!tcontext) { |
|
pr_err("SELinux: %s: unrecognized SID %d\n", |
|
__func__, tsid); |
|
goto out; |
|
} |
|
|
|
if (unlikely(!tclass)) { |
|
if (policydb->allow_unknown) |
|
goto allow; |
|
goto out; |
|
} |
|
|
|
context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, |
|
NULL); |
|
out: |
|
rcu_read_unlock(); |
|
return; |
|
allow: |
|
avd->allowed = 0xffffffff; |
|
goto out; |
|
} |
|
|
|
/* |
|
* Write the security context string representation of |
|
* the context structure `context' into a dynamically |
|
* allocated string of the correct size. Set `*scontext' |
|
* to point to this string and set `*scontext_len' to |
|
* the length of the string. |
|
*/ |
|
static int context_struct_to_string(struct policydb *p, |
|
struct context *context, |
|
char **scontext, u32 *scontext_len) |
|
{ |
|
char *scontextp; |
|
|
|
if (scontext) |
|
*scontext = NULL; |
|
*scontext_len = 0; |
|
|
|
if (context->len) { |
|
*scontext_len = context->len; |
|
if (scontext) { |
|
*scontext = kstrdup(context->str, GFP_ATOMIC); |
|
if (!(*scontext)) |
|
return -ENOMEM; |
|
} |
|
return 0; |
|
} |
|
|
|
/* Compute the size of the context. */ |
|
*scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1; |
|
*scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1; |
|
*scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1; |
|
*scontext_len += mls_compute_context_len(p, context); |
|
|
|
if (!scontext) |
|
return 0; |
|
|
|
/* Allocate space for the context; caller must free this space. */ |
|
scontextp = kmalloc(*scontext_len, GFP_ATOMIC); |
|
if (!scontextp) |
|
return -ENOMEM; |
|
*scontext = scontextp; |
|
|
|
/* |
|
* Copy the user name, role name and type name into the context. |
|
*/ |
|
scontextp += sprintf(scontextp, "%s:%s:%s", |
|
sym_name(p, SYM_USERS, context->user - 1), |
|
sym_name(p, SYM_ROLES, context->role - 1), |
|
sym_name(p, SYM_TYPES, context->type - 1)); |
|
|
|
mls_sid_to_context(p, context, &scontextp); |
|
|
|
*scontextp = 0; |
|
|
|
return 0; |
|
} |
|
|
|
static int sidtab_entry_to_string(struct policydb *p, |
|
struct sidtab *sidtab, |
|
struct sidtab_entry *entry, |
|
char **scontext, u32 *scontext_len) |
|
{ |
|
int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len); |
|
|
|
if (rc != -ENOENT) |
|
return rc; |
|
|
|
rc = context_struct_to_string(p, &entry->context, scontext, |
|
scontext_len); |
|
if (!rc && scontext) |
|
sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len); |
|
return rc; |
|
} |
|
|
|
#include "initial_sid_to_string.h" |
|
|
|
int security_sidtab_hash_stats(struct selinux_state *state, char *page) |
|
{ |
|
struct selinux_policy *policy; |
|
int rc; |
|
|
|
if (!selinux_initialized(state)) { |
|
pr_err("SELinux: %s: called before initial load_policy\n", |
|
__func__); |
|
return -EINVAL; |
|
} |
|
|
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
rc = sidtab_hash_stats(policy->sidtab, page); |
|
rcu_read_unlock(); |
|
|
|
return rc; |
|
} |
|
|
|
const char *security_get_initial_sid_context(u32 sid) |
|
{ |
|
if (unlikely(sid > SECINITSID_NUM)) |
|
return NULL; |
|
return initial_sid_to_string[sid]; |
|
} |
|
|
|
static int security_sid_to_context_core(struct selinux_state *state, |
|
u32 sid, char **scontext, |
|
u32 *scontext_len, int force, |
|
int only_invalid) |
|
{ |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
struct sidtab *sidtab; |
|
struct sidtab_entry *entry; |
|
int rc = 0; |
|
|
|
if (scontext) |
|
*scontext = NULL; |
|
*scontext_len = 0; |
|
|
|
if (!selinux_initialized(state)) { |
|
if (sid <= SECINITSID_NUM) { |
|
char *scontextp; |
|
const char *s = initial_sid_to_string[sid]; |
|
|
|
if (!s) |
|
return -EINVAL; |
|
*scontext_len = strlen(s) + 1; |
|
if (!scontext) |
|
return 0; |
|
scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC); |
|
if (!scontextp) |
|
return -ENOMEM; |
|
*scontext = scontextp; |
|
return 0; |
|
} |
|
pr_err("SELinux: %s: called before initial " |
|
"load_policy on unknown SID %d\n", __func__, sid); |
|
return -EINVAL; |
|
} |
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
policydb = &policy->policydb; |
|
sidtab = policy->sidtab; |
|
|
|
if (force) |
|
entry = sidtab_search_entry_force(sidtab, sid); |
|
else |
|
entry = sidtab_search_entry(sidtab, sid); |
|
if (!entry) { |
|
pr_err("SELinux: %s: unrecognized SID %d\n", |
|
__func__, sid); |
|
rc = -EINVAL; |
|
goto out_unlock; |
|
} |
|
if (only_invalid && !entry->context.len) |
|
goto out_unlock; |
|
|
|
rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext, |
|
scontext_len); |
|
|
|
out_unlock: |
|
rcu_read_unlock(); |
|
return rc; |
|
|
|
} |
|
|
|
/** |
|
* security_sid_to_context - Obtain a context for a given SID. |
|
* @sid: security identifier, SID |
|
* @scontext: security context |
|
* @scontext_len: length in bytes |
|
* |
|
* Write the string representation of the context associated with @sid |
|
* into a dynamically allocated string of the correct size. Set @scontext |
|
* to point to this string and set @scontext_len to the length of the string. |
|
*/ |
|
int security_sid_to_context(struct selinux_state *state, |
|
u32 sid, char **scontext, u32 *scontext_len) |
|
{ |
|
return security_sid_to_context_core(state, sid, scontext, |
|
scontext_len, 0, 0); |
|
} |
|
|
|
int security_sid_to_context_force(struct selinux_state *state, u32 sid, |
|
char **scontext, u32 *scontext_len) |
|
{ |
|
return security_sid_to_context_core(state, sid, scontext, |
|
scontext_len, 1, 0); |
|
} |
|
|
|
/** |
|
* security_sid_to_context_inval - Obtain a context for a given SID if it |
|
* is invalid. |
|
* @sid: security identifier, SID |
|
* @scontext: security context |
|
* @scontext_len: length in bytes |
|
* |
|
* Write the string representation of the context associated with @sid |
|
* into a dynamically allocated string of the correct size, but only if the |
|
* context is invalid in the current policy. Set @scontext to point to |
|
* this string (or NULL if the context is valid) and set @scontext_len to |
|
* the length of the string (or 0 if the context is valid). |
|
*/ |
|
int security_sid_to_context_inval(struct selinux_state *state, u32 sid, |
|
char **scontext, u32 *scontext_len) |
|
{ |
|
return security_sid_to_context_core(state, sid, scontext, |
|
scontext_len, 1, 1); |
|
} |
|
|
|
/* |
|
* Caveat: Mutates scontext. |
|
*/ |
|
static int string_to_context_struct(struct policydb *pol, |
|
struct sidtab *sidtabp, |
|
char *scontext, |
|
struct context *ctx, |
|
u32 def_sid) |
|
{ |
|
struct role_datum *role; |
|
struct type_datum *typdatum; |
|
struct user_datum *usrdatum; |
|
char *scontextp, *p, oldc; |
|
int rc = 0; |
|
|
|
context_init(ctx); |
|
|
|
/* Parse the security context. */ |
|
|
|
rc = -EINVAL; |
|
scontextp = (char *) scontext; |
|
|
|
/* Extract the user. */ |
|
p = scontextp; |
|
while (*p && *p != ':') |
|
p++; |
|
|
|
if (*p == 0) |
|
goto out; |
|
|
|
*p++ = 0; |
|
|
|
usrdatum = symtab_search(&pol->p_users, scontextp); |
|
if (!usrdatum) |
|
goto out; |
|
|
|
ctx->user = usrdatum->value; |
|
|
|
/* Extract role. */ |
|
scontextp = p; |
|
while (*p && *p != ':') |
|
p++; |
|
|
|
if (*p == 0) |
|
goto out; |
|
|
|
*p++ = 0; |
|
|
|
role = symtab_search(&pol->p_roles, scontextp); |
|
if (!role) |
|
goto out; |
|
ctx->role = role->value; |
|
|
|
/* Extract type. */ |
|
scontextp = p; |
|
while (*p && *p != ':') |
|
p++; |
|
oldc = *p; |
|
*p++ = 0; |
|
|
|
typdatum = symtab_search(&pol->p_types, scontextp); |
|
if (!typdatum || typdatum->attribute) |
|
goto out; |
|
|
|
ctx->type = typdatum->value; |
|
|
|
rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid); |
|
if (rc) |
|
goto out; |
|
|
|
/* Check the validity of the new context. */ |
|
rc = -EINVAL; |
|
if (!policydb_context_isvalid(pol, ctx)) |
|
goto out; |
|
rc = 0; |
|
out: |
|
if (rc) |
|
context_destroy(ctx); |
|
return rc; |
|
} |
|
|
|
static int security_context_to_sid_core(struct selinux_state *state, |
|
const char *scontext, u32 scontext_len, |
|
u32 *sid, u32 def_sid, gfp_t gfp_flags, |
|
int force) |
|
{ |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
struct sidtab *sidtab; |
|
char *scontext2, *str = NULL; |
|
struct context context; |
|
int rc = 0; |
|
|
|
/* An empty security context is never valid. */ |
|
if (!scontext_len) |
|
return -EINVAL; |
|
|
|
/* Copy the string to allow changes and ensure a NUL terminator */ |
|
scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags); |
|
if (!scontext2) |
|
return -ENOMEM; |
|
|
|
if (!selinux_initialized(state)) { |
|
int i; |
|
|
|
for (i = 1; i < SECINITSID_NUM; i++) { |
|
const char *s = initial_sid_to_string[i]; |
|
|
|
if (s && !strcmp(s, scontext2)) { |
|
*sid = i; |
|
goto out; |
|
} |
|
} |
|
*sid = SECINITSID_KERNEL; |
|
goto out; |
|
} |
|
*sid = SECSID_NULL; |
|
|
|
if (force) { |
|
/* Save another copy for storing in uninterpreted form */ |
|
rc = -ENOMEM; |
|
str = kstrdup(scontext2, gfp_flags); |
|
if (!str) |
|
goto out; |
|
} |
|
retry: |
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
policydb = &policy->policydb; |
|
sidtab = policy->sidtab; |
|
rc = string_to_context_struct(policydb, sidtab, scontext2, |
|
&context, def_sid); |
|
if (rc == -EINVAL && force) { |
|
context.str = str; |
|
context.len = strlen(str) + 1; |
|
str = NULL; |
|
} else if (rc) |
|
goto out_unlock; |
|
rc = sidtab_context_to_sid(sidtab, &context, sid); |
|
if (rc == -ESTALE) { |
|
rcu_read_unlock(); |
|
if (context.str) { |
|
str = context.str; |
|
context.str = NULL; |
|
} |
|
context_destroy(&context); |
|
goto retry; |
|
} |
|
context_destroy(&context); |
|
out_unlock: |
|
rcu_read_unlock(); |
|
out: |
|
kfree(scontext2); |
|
kfree(str); |
|
return rc; |
|
} |
|
|
|
/** |
|
* security_context_to_sid - Obtain a SID for a given security context. |
|
* @scontext: security context |
|
* @scontext_len: length in bytes |
|
* @sid: security identifier, SID |
|
* @gfp: context for the allocation |
|
* |
|
* Obtains a SID associated with the security context that |
|
* has the string representation specified by @scontext. |
|
* Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient |
|
* memory is available, or 0 on success. |
|
*/ |
|
int security_context_to_sid(struct selinux_state *state, |
|
const char *scontext, u32 scontext_len, u32 *sid, |
|
gfp_t gfp) |
|
{ |
|
return security_context_to_sid_core(state, scontext, scontext_len, |
|
sid, SECSID_NULL, gfp, 0); |
|
} |
|
|
|
int security_context_str_to_sid(struct selinux_state *state, |
|
const char *scontext, u32 *sid, gfp_t gfp) |
|
{ |
|
return security_context_to_sid(state, scontext, strlen(scontext), |
|
sid, gfp); |
|
} |
|
|
|
/** |
|
* security_context_to_sid_default - Obtain a SID for a given security context, |
|
* falling back to specified default if needed. |
|
* |
|
* @scontext: security context |
|
* @scontext_len: length in bytes |
|
* @sid: security identifier, SID |
|
* @def_sid: default SID to assign on error |
|
* |
|
* Obtains a SID associated with the security context that |
|
* has the string representation specified by @scontext. |
|
* The default SID is passed to the MLS layer to be used to allow |
|
* kernel labeling of the MLS field if the MLS field is not present |
|
* (for upgrading to MLS without full relabel). |
|
* Implicitly forces adding of the context even if it cannot be mapped yet. |
|
* Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient |
|
* memory is available, or 0 on success. |
|
*/ |
|
int security_context_to_sid_default(struct selinux_state *state, |
|
const char *scontext, u32 scontext_len, |
|
u32 *sid, u32 def_sid, gfp_t gfp_flags) |
|
{ |
|
return security_context_to_sid_core(state, scontext, scontext_len, |
|
sid, def_sid, gfp_flags, 1); |
|
} |
|
|
|
int security_context_to_sid_force(struct selinux_state *state, |
|
const char *scontext, u32 scontext_len, |
|
u32 *sid) |
|
{ |
|
return security_context_to_sid_core(state, scontext, scontext_len, |
|
sid, SECSID_NULL, GFP_KERNEL, 1); |
|
} |
|
|
|
static int compute_sid_handle_invalid_context( |
|
struct selinux_state *state, |
|
struct selinux_policy *policy, |
|
struct sidtab_entry *sentry, |
|
struct sidtab_entry *tentry, |
|
u16 tclass, |
|
struct context *newcontext) |
|
{ |
|
struct policydb *policydb = &policy->policydb; |
|
struct sidtab *sidtab = policy->sidtab; |
|
char *s = NULL, *t = NULL, *n = NULL; |
|
u32 slen, tlen, nlen; |
|
struct audit_buffer *ab; |
|
|
|
if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen)) |
|
goto out; |
|
if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen)) |
|
goto out; |
|
if (context_struct_to_string(policydb, newcontext, &n, &nlen)) |
|
goto out; |
|
ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR); |
|
audit_log_format(ab, |
|
"op=security_compute_sid invalid_context="); |
|
/* no need to record the NUL with untrusted strings */ |
|
audit_log_n_untrustedstring(ab, n, nlen - 1); |
|
audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s", |
|
s, t, sym_name(policydb, SYM_CLASSES, tclass-1)); |
|
audit_log_end(ab); |
|
out: |
|
kfree(s); |
|
kfree(t); |
|
kfree(n); |
|
if (!enforcing_enabled(state)) |
|
return 0; |
|
return -EACCES; |
|
} |
|
|
|
static void filename_compute_type(struct policydb *policydb, |
|
struct context *newcontext, |
|
u32 stype, u32 ttype, u16 tclass, |
|
const char *objname) |
|
{ |
|
struct filename_trans_key ft; |
|
struct filename_trans_datum *datum; |
|
|
|
/* |
|
* Most filename trans rules are going to live in specific directories |
|
* like /dev or /var/run. This bitmap will quickly skip rule searches |
|
* if the ttype does not contain any rules. |
|
*/ |
|
if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype)) |
|
return; |
|
|
|
ft.ttype = ttype; |
|
ft.tclass = tclass; |
|
ft.name = objname; |
|
|
|
datum = policydb_filenametr_search(policydb, &ft); |
|
while (datum) { |
|
if (ebitmap_get_bit(&datum->stypes, stype - 1)) { |
|
newcontext->type = datum->otype; |
|
return; |
|
} |
|
datum = datum->next; |
|
} |
|
} |
|
|
|
static int security_compute_sid(struct selinux_state *state, |
|
u32 ssid, |
|
u32 tsid, |
|
u16 orig_tclass, |
|
u32 specified, |
|
const char *objname, |
|
u32 *out_sid, |
|
bool kern) |
|
{ |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
struct sidtab *sidtab; |
|
struct class_datum *cladatum; |
|
struct context *scontext, *tcontext, newcontext; |
|
struct sidtab_entry *sentry, *tentry; |
|
struct avtab_key avkey; |
|
struct avtab_datum *avdatum; |
|
struct avtab_node *node; |
|
u16 tclass; |
|
int rc = 0; |
|
bool sock; |
|
|
|
if (!selinux_initialized(state)) { |
|
switch (orig_tclass) { |
|
case SECCLASS_PROCESS: /* kernel value */ |
|
*out_sid = ssid; |
|
break; |
|
default: |
|
*out_sid = tsid; |
|
break; |
|
} |
|
goto out; |
|
} |
|
|
|
retry: |
|
cladatum = NULL; |
|
context_init(&newcontext); |
|
|
|
rcu_read_lock(); |
|
|
|
policy = rcu_dereference(state->policy); |
|
|
|
if (kern) { |
|
tclass = unmap_class(&policy->map, orig_tclass); |
|
sock = security_is_socket_class(orig_tclass); |
|
} else { |
|
tclass = orig_tclass; |
|
sock = security_is_socket_class(map_class(&policy->map, |
|
tclass)); |
|
} |
|
|
|
policydb = &policy->policydb; |
|
sidtab = policy->sidtab; |
|
|
|
sentry = sidtab_search_entry(sidtab, ssid); |
|
if (!sentry) { |
|
pr_err("SELinux: %s: unrecognized SID %d\n", |
|
__func__, ssid); |
|
rc = -EINVAL; |
|
goto out_unlock; |
|
} |
|
tentry = sidtab_search_entry(sidtab, tsid); |
|
if (!tentry) { |
|
pr_err("SELinux: %s: unrecognized SID %d\n", |
|
__func__, tsid); |
|
rc = -EINVAL; |
|
goto out_unlock; |
|
} |
|
|
|
scontext = &sentry->context; |
|
tcontext = &tentry->context; |
|
|
|
if (tclass && tclass <= policydb->p_classes.nprim) |
|
cladatum = policydb->class_val_to_struct[tclass - 1]; |
|
|
|
/* Set the user identity. */ |
|
switch (specified) { |
|
case AVTAB_TRANSITION: |
|
case AVTAB_CHANGE: |
|
if (cladatum && cladatum->default_user == DEFAULT_TARGET) { |
|
newcontext.user = tcontext->user; |
|
} else { |
|
/* notice this gets both DEFAULT_SOURCE and unset */ |
|
/* Use the process user identity. */ |
|
newcontext.user = scontext->user; |
|
} |
|
break; |
|
case AVTAB_MEMBER: |
|
/* Use the related object owner. */ |
|
newcontext.user = tcontext->user; |
|
break; |
|
} |
|
|
|
/* Set the role to default values. */ |
|
if (cladatum && cladatum->default_role == DEFAULT_SOURCE) { |
|
newcontext.role = scontext->role; |
|
} else if (cladatum && cladatum->default_role == DEFAULT_TARGET) { |
|
newcontext.role = tcontext->role; |
|
} else { |
|
if ((tclass == policydb->process_class) || sock) |
|
newcontext.role = scontext->role; |
|
else |
|
newcontext.role = OBJECT_R_VAL; |
|
} |
|
|
|
/* Set the type to default values. */ |
|
if (cladatum && cladatum->default_type == DEFAULT_SOURCE) { |
|
newcontext.type = scontext->type; |
|
} else if (cladatum && cladatum->default_type == DEFAULT_TARGET) { |
|
newcontext.type = tcontext->type; |
|
} else { |
|
if ((tclass == policydb->process_class) || sock) { |
|
/* Use the type of process. */ |
|
newcontext.type = scontext->type; |
|
} else { |
|
/* Use the type of the related object. */ |
|
newcontext.type = tcontext->type; |
|
} |
|
} |
|
|
|
/* Look for a type transition/member/change rule. */ |
|
avkey.source_type = scontext->type; |
|
avkey.target_type = tcontext->type; |
|
avkey.target_class = tclass; |
|
avkey.specified = specified; |
|
avdatum = avtab_search(&policydb->te_avtab, &avkey); |
|
|
|
/* If no permanent rule, also check for enabled conditional rules */ |
|
if (!avdatum) { |
|
node = avtab_search_node(&policydb->te_cond_avtab, &avkey); |
|
for (; node; node = avtab_search_node_next(node, specified)) { |
|
if (node->key.specified & AVTAB_ENABLED) { |
|
avdatum = &node->datum; |
|
break; |
|
} |
|
} |
|
} |
|
|
|
if (avdatum) { |
|
/* Use the type from the type transition/member/change rule. */ |
|
newcontext.type = avdatum->u.data; |
|
} |
|
|
|
/* if we have a objname this is a file trans check so check those rules */ |
|
if (objname) |
|
filename_compute_type(policydb, &newcontext, scontext->type, |
|
tcontext->type, tclass, objname); |
|
|
|
/* Check for class-specific changes. */ |
|
if (specified & AVTAB_TRANSITION) { |
|
/* Look for a role transition rule. */ |
|
struct role_trans_datum *rtd; |
|
struct role_trans_key rtk = { |
|
.role = scontext->role, |
|
.type = tcontext->type, |
|
.tclass = tclass, |
|
}; |
|
|
|
rtd = policydb_roletr_search(policydb, &rtk); |
|
if (rtd) |
|
newcontext.role = rtd->new_role; |
|
} |
|
|
|
/* Set the MLS attributes. |
|
This is done last because it may allocate memory. */ |
|
rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified, |
|
&newcontext, sock); |
|
if (rc) |
|
goto out_unlock; |
|
|
|
/* Check the validity of the context. */ |
|
if (!policydb_context_isvalid(policydb, &newcontext)) { |
|
rc = compute_sid_handle_invalid_context(state, policy, sentry, |
|
tentry, tclass, |
|
&newcontext); |
|
if (rc) |
|
goto out_unlock; |
|
} |
|
/* Obtain the sid for the context. */ |
|
rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid); |
|
if (rc == -ESTALE) { |
|
rcu_read_unlock(); |
|
context_destroy(&newcontext); |
|
goto retry; |
|
} |
|
out_unlock: |
|
rcu_read_unlock(); |
|
context_destroy(&newcontext); |
|
out: |
|
return rc; |
|
} |
|
|
|
/** |
|
* security_transition_sid - Compute the SID for a new subject/object. |
|
* @ssid: source security identifier |
|
* @tsid: target security identifier |
|
* @tclass: target security class |
|
* @out_sid: security identifier for new subject/object |
|
* |
|
* Compute a SID to use for labeling a new subject or object in the |
|
* class @tclass based on a SID pair (@ssid, @tsid). |
|
* Return -%EINVAL if any of the parameters are invalid, -%ENOMEM |
|
* if insufficient memory is available, or %0 if the new SID was |
|
* computed successfully. |
|
*/ |
|
int security_transition_sid(struct selinux_state *state, |
|
u32 ssid, u32 tsid, u16 tclass, |
|
const struct qstr *qstr, u32 *out_sid) |
|
{ |
|
return security_compute_sid(state, ssid, tsid, tclass, |
|
AVTAB_TRANSITION, |
|
qstr ? qstr->name : NULL, out_sid, true); |
|
} |
|
|
|
int security_transition_sid_user(struct selinux_state *state, |
|
u32 ssid, u32 tsid, u16 tclass, |
|
const char *objname, u32 *out_sid) |
|
{ |
|
return security_compute_sid(state, ssid, tsid, tclass, |
|
AVTAB_TRANSITION, |
|
objname, out_sid, false); |
|
} |
|
|
|
/** |
|
* security_member_sid - Compute the SID for member selection. |
|
* @ssid: source security identifier |
|
* @tsid: target security identifier |
|
* @tclass: target security class |
|
* @out_sid: security identifier for selected member |
|
* |
|
* Compute a SID to use when selecting a member of a polyinstantiated |
|
* object of class @tclass based on a SID pair (@ssid, @tsid). |
|
* Return -%EINVAL if any of the parameters are invalid, -%ENOMEM |
|
* if insufficient memory is available, or %0 if the SID was |
|
* computed successfully. |
|
*/ |
|
int security_member_sid(struct selinux_state *state, |
|
u32 ssid, |
|
u32 tsid, |
|
u16 tclass, |
|
u32 *out_sid) |
|
{ |
|
return security_compute_sid(state, ssid, tsid, tclass, |
|
AVTAB_MEMBER, NULL, |
|
out_sid, false); |
|
} |
|
|
|
/** |
|
* security_change_sid - Compute the SID for object relabeling. |
|
* @ssid: source security identifier |
|
* @tsid: target security identifier |
|
* @tclass: target security class |
|
* @out_sid: security identifier for selected member |
|
* |
|
* Compute a SID to use for relabeling an object of class @tclass |
|
* based on a SID pair (@ssid, @tsid). |
|
* Return -%EINVAL if any of the parameters are invalid, -%ENOMEM |
|
* if insufficient memory is available, or %0 if the SID was |
|
* computed successfully. |
|
*/ |
|
int security_change_sid(struct selinux_state *state, |
|
u32 ssid, |
|
u32 tsid, |
|
u16 tclass, |
|
u32 *out_sid) |
|
{ |
|
return security_compute_sid(state, |
|
ssid, tsid, tclass, AVTAB_CHANGE, NULL, |
|
out_sid, false); |
|
} |
|
|
|
static inline int convert_context_handle_invalid_context( |
|
struct selinux_state *state, |
|
struct policydb *policydb, |
|
struct context *context) |
|
{ |
|
char *s; |
|
u32 len; |
|
|
|
if (enforcing_enabled(state)) |
|
return -EINVAL; |
|
|
|
if (!context_struct_to_string(policydb, context, &s, &len)) { |
|
pr_warn("SELinux: Context %s would be invalid if enforcing\n", |
|
s); |
|
kfree(s); |
|
} |
|
return 0; |
|
} |
|
|
|
/* |
|
* Convert the values in the security context |
|
* structure `oldc' from the values specified |
|
* in the policy `p->oldp' to the values specified |
|
* in the policy `p->newp', storing the new context |
|
* in `newc'. Verify that the context is valid |
|
* under the new policy. |
|
*/ |
|
static int convert_context(struct context *oldc, struct context *newc, void *p) |
|
{ |
|
struct convert_context_args *args; |
|
struct ocontext *oc; |
|
struct role_datum *role; |
|
struct type_datum *typdatum; |
|
struct user_datum *usrdatum; |
|
char *s; |
|
u32 len; |
|
int rc; |
|
|
|
args = p; |
|
|
|
if (oldc->str) { |
|
s = kstrdup(oldc->str, GFP_KERNEL); |
|
if (!s) |
|
return -ENOMEM; |
|
|
|
rc = string_to_context_struct(args->newp, NULL, s, |
|
newc, SECSID_NULL); |
|
if (rc == -EINVAL) { |
|
/* |
|
* Retain string representation for later mapping. |
|
* |
|
* IMPORTANT: We need to copy the contents of oldc->str |
|
* back into s again because string_to_context_struct() |
|
* may have garbled it. |
|
*/ |
|
memcpy(s, oldc->str, oldc->len); |
|
context_init(newc); |
|
newc->str = s; |
|
newc->len = oldc->len; |
|
return 0; |
|
} |
|
kfree(s); |
|
if (rc) { |
|
/* Other error condition, e.g. ENOMEM. */ |
|
pr_err("SELinux: Unable to map context %s, rc = %d.\n", |
|
oldc->str, -rc); |
|
return rc; |
|
} |
|
pr_info("SELinux: Context %s became valid (mapped).\n", |
|
oldc->str); |
|
return 0; |
|
} |
|
|
|
context_init(newc); |
|
|
|
/* Convert the user. */ |
|
rc = -EINVAL; |
|
usrdatum = symtab_search(&args->newp->p_users, |
|
sym_name(args->oldp, |
|
SYM_USERS, oldc->user - 1)); |
|
if (!usrdatum) |
|
goto bad; |
|
newc->user = usrdatum->value; |
|
|
|
/* Convert the role. */ |
|
rc = -EINVAL; |
|
role = symtab_search(&args->newp->p_roles, |
|
sym_name(args->oldp, SYM_ROLES, oldc->role - 1)); |
|
if (!role) |
|
goto bad; |
|
newc->role = role->value; |
|
|
|
/* Convert the type. */ |
|
rc = -EINVAL; |
|
typdatum = symtab_search(&args->newp->p_types, |
|
sym_name(args->oldp, |
|
SYM_TYPES, oldc->type - 1)); |
|
if (!typdatum) |
|
goto bad; |
|
newc->type = typdatum->value; |
|
|
|
/* Convert the MLS fields if dealing with MLS policies */ |
|
if (args->oldp->mls_enabled && args->newp->mls_enabled) { |
|
rc = mls_convert_context(args->oldp, args->newp, oldc, newc); |
|
if (rc) |
|
goto bad; |
|
} else if (!args->oldp->mls_enabled && args->newp->mls_enabled) { |
|
/* |
|
* Switching between non-MLS and MLS policy: |
|
* ensure that the MLS fields of the context for all |
|
* existing entries in the sidtab are filled in with a |
|
* suitable default value, likely taken from one of the |
|
* initial SIDs. |
|
*/ |
|
oc = args->newp->ocontexts[OCON_ISID]; |
|
while (oc && oc->sid[0] != SECINITSID_UNLABELED) |
|
oc = oc->next; |
|
rc = -EINVAL; |
|
if (!oc) { |
|
pr_err("SELinux: unable to look up" |
|
" the initial SIDs list\n"); |
|
goto bad; |
|
} |
|
rc = mls_range_set(newc, &oc->context[0].range); |
|
if (rc) |
|
goto bad; |
|
} |
|
|
|
/* Check the validity of the new context. */ |
|
if (!policydb_context_isvalid(args->newp, newc)) { |
|
rc = convert_context_handle_invalid_context(args->state, |
|
args->oldp, |
|
oldc); |
|
if (rc) |
|
goto bad; |
|
} |
|
|
|
return 0; |
|
bad: |
|
/* Map old representation to string and save it. */ |
|
rc = context_struct_to_string(args->oldp, oldc, &s, &len); |
|
if (rc) |
|
return rc; |
|
context_destroy(newc); |
|
newc->str = s; |
|
newc->len = len; |
|
pr_info("SELinux: Context %s became invalid (unmapped).\n", |
|
newc->str); |
|
return 0; |
|
} |
|
|
|
static void security_load_policycaps(struct selinux_state *state, |
|
struct selinux_policy *policy) |
|
{ |
|
struct policydb *p; |
|
unsigned int i; |
|
struct ebitmap_node *node; |
|
|
|
p = &policy->policydb; |
|
|
|
for (i = 0; i < ARRAY_SIZE(state->policycap); i++) |
|
WRITE_ONCE(state->policycap[i], |
|
ebitmap_get_bit(&p->policycaps, i)); |
|
|
|
for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++) |
|
pr_info("SELinux: policy capability %s=%d\n", |
|
selinux_policycap_names[i], |
|
ebitmap_get_bit(&p->policycaps, i)); |
|
|
|
ebitmap_for_each_positive_bit(&p->policycaps, node, i) { |
|
if (i >= ARRAY_SIZE(selinux_policycap_names)) |
|
pr_info("SELinux: unknown policy capability %u\n", |
|
i); |
|
} |
|
} |
|
|
|
static int security_preserve_bools(struct selinux_policy *oldpolicy, |
|
struct selinux_policy *newpolicy); |
|
|
|
static void selinux_policy_free(struct selinux_policy *policy) |
|
{ |
|
if (!policy) |
|
return; |
|
|
|
sidtab_destroy(policy->sidtab); |
|
kfree(policy->map.mapping); |
|
policydb_destroy(&policy->policydb); |
|
kfree(policy->sidtab); |
|
kfree(policy); |
|
} |
|
|
|
static void selinux_policy_cond_free(struct selinux_policy *policy) |
|
{ |
|
cond_policydb_destroy_dup(&policy->policydb); |
|
kfree(policy); |
|
} |
|
|
|
void selinux_policy_cancel(struct selinux_state *state, |
|
struct selinux_load_state *load_state) |
|
{ |
|
struct selinux_policy *oldpolicy; |
|
|
|
oldpolicy = rcu_dereference_protected(state->policy, |
|
lockdep_is_held(&state->policy_mutex)); |
|
|
|
sidtab_cancel_convert(oldpolicy->sidtab); |
|
selinux_policy_free(load_state->policy); |
|
kfree(load_state->convert_data); |
|
} |
|
|
|
static void selinux_notify_policy_change(struct selinux_state *state, |
|
u32 seqno) |
|
{ |
|
/* Flush external caches and notify userspace of policy load */ |
|
avc_ss_reset(state->avc, seqno); |
|
selnl_notify_policyload(seqno); |
|
selinux_status_update_policyload(state, seqno); |
|
selinux_netlbl_cache_invalidate(); |
|
selinux_xfrm_notify_policyload(); |
|
selinux_ima_measure_state(state); |
|
} |
|
|
|
void selinux_policy_commit(struct selinux_state *state, |
|
struct selinux_load_state *load_state) |
|
{ |
|
struct selinux_policy *oldpolicy, *newpolicy = load_state->policy; |
|
unsigned long flags; |
|
u32 seqno; |
|
|
|
oldpolicy = rcu_dereference_protected(state->policy, |
|
lockdep_is_held(&state->policy_mutex)); |
|
|
|
/* If switching between different policy types, log MLS status */ |
|
if (oldpolicy) { |
|
if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled) |
|
pr_info("SELinux: Disabling MLS support...\n"); |
|
else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled) |
|
pr_info("SELinux: Enabling MLS support...\n"); |
|
} |
|
|
|
/* Set latest granting seqno for new policy. */ |
|
if (oldpolicy) |
|
newpolicy->latest_granting = oldpolicy->latest_granting + 1; |
|
else |
|
newpolicy->latest_granting = 1; |
|
seqno = newpolicy->latest_granting; |
|
|
|
/* Install the new policy. */ |
|
if (oldpolicy) { |
|
sidtab_freeze_begin(oldpolicy->sidtab, &flags); |
|
rcu_assign_pointer(state->policy, newpolicy); |
|
sidtab_freeze_end(oldpolicy->sidtab, &flags); |
|
} else { |
|
rcu_assign_pointer(state->policy, newpolicy); |
|
} |
|
|
|
/* Load the policycaps from the new policy */ |
|
security_load_policycaps(state, newpolicy); |
|
|
|
if (!selinux_initialized(state)) { |
|
/* |
|
* After first policy load, the security server is |
|
* marked as initialized and ready to handle requests and |
|
* any objects created prior to policy load are then labeled. |
|
*/ |
|
selinux_mark_initialized(state); |
|
selinux_complete_init(); |
|
} |
|
|
|
/* Free the old policy */ |
|
synchronize_rcu(); |
|
selinux_policy_free(oldpolicy); |
|
kfree(load_state->convert_data); |
|
|
|
/* Notify others of the policy change */ |
|
selinux_notify_policy_change(state, seqno); |
|
} |
|
|
|
/** |
|
* security_load_policy - Load a security policy configuration. |
|
* @data: binary policy data |
|
* @len: length of data in bytes |
|
* |
|
* Load a new set of security policy configuration data, |
|
* validate it and convert the SID table as necessary. |
|
* This function will flush the access vector cache after |
|
* loading the new policy. |
|
*/ |
|
int security_load_policy(struct selinux_state *state, void *data, size_t len, |
|
struct selinux_load_state *load_state) |
|
{ |
|
struct selinux_policy *newpolicy, *oldpolicy; |
|
struct selinux_policy_convert_data *convert_data; |
|
int rc = 0; |
|
struct policy_file file = { data, len }, *fp = &file; |
|
|
|
newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL); |
|
if (!newpolicy) |
|
return -ENOMEM; |
|
|
|
newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL); |
|
if (!newpolicy->sidtab) { |
|
rc = -ENOMEM; |
|
goto err_policy; |
|
} |
|
|
|
rc = policydb_read(&newpolicy->policydb, fp); |
|
if (rc) |
|
goto err_sidtab; |
|
|
|
newpolicy->policydb.len = len; |
|
rc = selinux_set_mapping(&newpolicy->policydb, secclass_map, |
|
&newpolicy->map); |
|
if (rc) |
|
goto err_policydb; |
|
|
|
rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab); |
|
if (rc) { |
|
pr_err("SELinux: unable to load the initial SIDs\n"); |
|
goto err_mapping; |
|
} |
|
|
|
if (!selinux_initialized(state)) { |
|
/* First policy load, so no need to preserve state from old policy */ |
|
load_state->policy = newpolicy; |
|
load_state->convert_data = NULL; |
|
return 0; |
|
} |
|
|
|
oldpolicy = rcu_dereference_protected(state->policy, |
|
lockdep_is_held(&state->policy_mutex)); |
|
|
|
/* Preserve active boolean values from the old policy */ |
|
rc = security_preserve_bools(oldpolicy, newpolicy); |
|
if (rc) { |
|
pr_err("SELinux: unable to preserve booleans\n"); |
|
goto err_free_isids; |
|
} |
|
|
|
convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL); |
|
if (!convert_data) { |
|
rc = -ENOMEM; |
|
goto err_free_isids; |
|
} |
|
|
|
/* |
|
* Convert the internal representations of contexts |
|
* in the new SID table. |
|
*/ |
|
convert_data->args.state = state; |
|
convert_data->args.oldp = &oldpolicy->policydb; |
|
convert_data->args.newp = &newpolicy->policydb; |
|
|
|
convert_data->sidtab_params.func = convert_context; |
|
convert_data->sidtab_params.args = &convert_data->args; |
|
convert_data->sidtab_params.target = newpolicy->sidtab; |
|
|
|
rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params); |
|
if (rc) { |
|
pr_err("SELinux: unable to convert the internal" |
|
" representation of contexts in the new SID" |
|
" table\n"); |
|
goto err_free_convert_data; |
|
} |
|
|
|
load_state->policy = newpolicy; |
|
load_state->convert_data = convert_data; |
|
return 0; |
|
|
|
err_free_convert_data: |
|
kfree(convert_data); |
|
err_free_isids: |
|
sidtab_destroy(newpolicy->sidtab); |
|
err_mapping: |
|
kfree(newpolicy->map.mapping); |
|
err_policydb: |
|
policydb_destroy(&newpolicy->policydb); |
|
err_sidtab: |
|
kfree(newpolicy->sidtab); |
|
err_policy: |
|
kfree(newpolicy); |
|
|
|
return rc; |
|
} |
|
|
|
/** |
|
* security_port_sid - Obtain the SID for a port. |
|
* @protocol: protocol number |
|
* @port: port number |
|
* @out_sid: security identifier |
|
*/ |
|
int security_port_sid(struct selinux_state *state, |
|
u8 protocol, u16 port, u32 *out_sid) |
|
{ |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
struct sidtab *sidtab; |
|
struct ocontext *c; |
|
int rc; |
|
|
|
if (!selinux_initialized(state)) { |
|
*out_sid = SECINITSID_PORT; |
|
return 0; |
|
} |
|
|
|
retry: |
|
rc = 0; |
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
policydb = &policy->policydb; |
|
sidtab = policy->sidtab; |
|
|
|
c = policydb->ocontexts[OCON_PORT]; |
|
while (c) { |
|
if (c->u.port.protocol == protocol && |
|
c->u.port.low_port <= port && |
|
c->u.port.high_port >= port) |
|
break; |
|
c = c->next; |
|
} |
|
|
|
if (c) { |
|
if (!c->sid[0]) { |
|
rc = sidtab_context_to_sid(sidtab, &c->context[0], |
|
&c->sid[0]); |
|
if (rc == -ESTALE) { |
|
rcu_read_unlock(); |
|
goto retry; |
|
} |
|
if (rc) |
|
goto out; |
|
} |
|
*out_sid = c->sid[0]; |
|
} else { |
|
*out_sid = SECINITSID_PORT; |
|
} |
|
|
|
out: |
|
rcu_read_unlock(); |
|
return rc; |
|
} |
|
|
|
/** |
|
* security_pkey_sid - Obtain the SID for a pkey. |
|
* @subnet_prefix: Subnet Prefix |
|
* @pkey_num: pkey number |
|
* @out_sid: security identifier |
|
*/ |
|
int security_ib_pkey_sid(struct selinux_state *state, |
|
u64 subnet_prefix, u16 pkey_num, u32 *out_sid) |
|
{ |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
struct sidtab *sidtab; |
|
struct ocontext *c; |
|
int rc; |
|
|
|
if (!selinux_initialized(state)) { |
|
*out_sid = SECINITSID_UNLABELED; |
|
return 0; |
|
} |
|
|
|
retry: |
|
rc = 0; |
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
policydb = &policy->policydb; |
|
sidtab = policy->sidtab; |
|
|
|
c = policydb->ocontexts[OCON_IBPKEY]; |
|
while (c) { |
|
if (c->u.ibpkey.low_pkey <= pkey_num && |
|
c->u.ibpkey.high_pkey >= pkey_num && |
|
c->u.ibpkey.subnet_prefix == subnet_prefix) |
|
break; |
|
|
|
c = c->next; |
|
} |
|
|
|
if (c) { |
|
if (!c->sid[0]) { |
|
rc = sidtab_context_to_sid(sidtab, |
|
&c->context[0], |
|
&c->sid[0]); |
|
if (rc == -ESTALE) { |
|
rcu_read_unlock(); |
|
goto retry; |
|
} |
|
if (rc) |
|
goto out; |
|
} |
|
*out_sid = c->sid[0]; |
|
} else |
|
*out_sid = SECINITSID_UNLABELED; |
|
|
|
out: |
|
rcu_read_unlock(); |
|
return rc; |
|
} |
|
|
|
/** |
|
* security_ib_endport_sid - Obtain the SID for a subnet management interface. |
|
* @dev_name: device name |
|
* @port: port number |
|
* @out_sid: security identifier |
|
*/ |
|
int security_ib_endport_sid(struct selinux_state *state, |
|
const char *dev_name, u8 port_num, u32 *out_sid) |
|
{ |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
struct sidtab *sidtab; |
|
struct ocontext *c; |
|
int rc; |
|
|
|
if (!selinux_initialized(state)) { |
|
*out_sid = SECINITSID_UNLABELED; |
|
return 0; |
|
} |
|
|
|
retry: |
|
rc = 0; |
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
policydb = &policy->policydb; |
|
sidtab = policy->sidtab; |
|
|
|
c = policydb->ocontexts[OCON_IBENDPORT]; |
|
while (c) { |
|
if (c->u.ibendport.port == port_num && |
|
!strncmp(c->u.ibendport.dev_name, |
|
dev_name, |
|
IB_DEVICE_NAME_MAX)) |
|
break; |
|
|
|
c = c->next; |
|
} |
|
|
|
if (c) { |
|
if (!c->sid[0]) { |
|
rc = sidtab_context_to_sid(sidtab, &c->context[0], |
|
&c->sid[0]); |
|
if (rc == -ESTALE) { |
|
rcu_read_unlock(); |
|
goto retry; |
|
} |
|
if (rc) |
|
goto out; |
|
} |
|
*out_sid = c->sid[0]; |
|
} else |
|
*out_sid = SECINITSID_UNLABELED; |
|
|
|
out: |
|
rcu_read_unlock(); |
|
return rc; |
|
} |
|
|
|
/** |
|
* security_netif_sid - Obtain the SID for a network interface. |
|
* @name: interface name |
|
* @if_sid: interface SID |
|
*/ |
|
int security_netif_sid(struct selinux_state *state, |
|
char *name, u32 *if_sid) |
|
{ |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
struct sidtab *sidtab; |
|
int rc; |
|
struct ocontext *c; |
|
|
|
if (!selinux_initialized(state)) { |
|
*if_sid = SECINITSID_NETIF; |
|
return 0; |
|
} |
|
|
|
retry: |
|
rc = 0; |
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
policydb = &policy->policydb; |
|
sidtab = policy->sidtab; |
|
|
|
c = policydb->ocontexts[OCON_NETIF]; |
|
while (c) { |
|
if (strcmp(name, c->u.name) == 0) |
|
break; |
|
c = c->next; |
|
} |
|
|
|
if (c) { |
|
if (!c->sid[0] || !c->sid[1]) { |
|
rc = sidtab_context_to_sid(sidtab, &c->context[0], |
|
&c->sid[0]); |
|
if (rc == -ESTALE) { |
|
rcu_read_unlock(); |
|
goto retry; |
|
} |
|
if (rc) |
|
goto out; |
|
rc = sidtab_context_to_sid(sidtab, &c->context[1], |
|
&c->sid[1]); |
|
if (rc == -ESTALE) { |
|
rcu_read_unlock(); |
|
goto retry; |
|
} |
|
if (rc) |
|
goto out; |
|
} |
|
*if_sid = c->sid[0]; |
|
} else |
|
*if_sid = SECINITSID_NETIF; |
|
|
|
out: |
|
rcu_read_unlock(); |
|
return rc; |
|
} |
|
|
|
static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask) |
|
{ |
|
int i, fail = 0; |
|
|
|
for (i = 0; i < 4; i++) |
|
if (addr[i] != (input[i] & mask[i])) { |
|
fail = 1; |
|
break; |
|
} |
|
|
|
return !fail; |
|
} |
|
|
|
/** |
|
* security_node_sid - Obtain the SID for a node (host). |
|
* @domain: communication domain aka address family |
|
* @addrp: address |
|
* @addrlen: address length in bytes |
|
* @out_sid: security identifier |
|
*/ |
|
int security_node_sid(struct selinux_state *state, |
|
u16 domain, |
|
void *addrp, |
|
u32 addrlen, |
|
u32 *out_sid) |
|
{ |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
struct sidtab *sidtab; |
|
int rc; |
|
struct ocontext *c; |
|
|
|
if (!selinux_initialized(state)) { |
|
*out_sid = SECINITSID_NODE; |
|
return 0; |
|
} |
|
|
|
retry: |
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
policydb = &policy->policydb; |
|
sidtab = policy->sidtab; |
|
|
|
switch (domain) { |
|
case AF_INET: { |
|
u32 addr; |
|
|
|
rc = -EINVAL; |
|
if (addrlen != sizeof(u32)) |
|
goto out; |
|
|
|
addr = *((u32 *)addrp); |
|
|
|
c = policydb->ocontexts[OCON_NODE]; |
|
while (c) { |
|
if (c->u.node.addr == (addr & c->u.node.mask)) |
|
break; |
|
c = c->next; |
|
} |
|
break; |
|
} |
|
|
|
case AF_INET6: |
|
rc = -EINVAL; |
|
if (addrlen != sizeof(u64) * 2) |
|
goto out; |
|
c = policydb->ocontexts[OCON_NODE6]; |
|
while (c) { |
|
if (match_ipv6_addrmask(addrp, c->u.node6.addr, |
|
c->u.node6.mask)) |
|
break; |
|
c = c->next; |
|
} |
|
break; |
|
|
|
default: |
|
rc = 0; |
|
*out_sid = SECINITSID_NODE; |
|
goto out; |
|
} |
|
|
|
if (c) { |
|
if (!c->sid[0]) { |
|
rc = sidtab_context_to_sid(sidtab, |
|
&c->context[0], |
|
&c->sid[0]); |
|
if (rc == -ESTALE) { |
|
rcu_read_unlock(); |
|
goto retry; |
|
} |
|
if (rc) |
|
goto out; |
|
} |
|
*out_sid = c->sid[0]; |
|
} else { |
|
*out_sid = SECINITSID_NODE; |
|
} |
|
|
|
rc = 0; |
|
out: |
|
rcu_read_unlock(); |
|
return rc; |
|
} |
|
|
|
#define SIDS_NEL 25 |
|
|
|
/** |
|
* security_get_user_sids - Obtain reachable SIDs for a user. |
|
* @fromsid: starting SID |
|
* @username: username |
|
* @sids: array of reachable SIDs for user |
|
* @nel: number of elements in @sids |
|
* |
|
* Generate the set of SIDs for legal security contexts |
|
* for a given user that can be reached by @fromsid. |
|
* Set *@sids to point to a dynamically allocated |
|
* array containing the set of SIDs. Set *@nel to the |
|
* number of elements in the array. |
|
*/ |
|
|
|
int security_get_user_sids(struct selinux_state *state, |
|
u32 fromsid, |
|
char *username, |
|
u32 **sids, |
|
u32 *nel) |
|
{ |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
struct sidtab *sidtab; |
|
struct context *fromcon, usercon; |
|
u32 *mysids = NULL, *mysids2, sid; |
|
u32 i, j, mynel, maxnel = SIDS_NEL; |
|
struct user_datum *user; |
|
struct role_datum *role; |
|
struct ebitmap_node *rnode, *tnode; |
|
int rc; |
|
|
|
*sids = NULL; |
|
*nel = 0; |
|
|
|
if (!selinux_initialized(state)) |
|
return 0; |
|
|
|
mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL); |
|
if (!mysids) |
|
return -ENOMEM; |
|
|
|
retry: |
|
mynel = 0; |
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
policydb = &policy->policydb; |
|
sidtab = policy->sidtab; |
|
|
|
context_init(&usercon); |
|
|
|
rc = -EINVAL; |
|
fromcon = sidtab_search(sidtab, fromsid); |
|
if (!fromcon) |
|
goto out_unlock; |
|
|
|
rc = -EINVAL; |
|
user = symtab_search(&policydb->p_users, username); |
|
if (!user) |
|
goto out_unlock; |
|
|
|
usercon.user = user->value; |
|
|
|
ebitmap_for_each_positive_bit(&user->roles, rnode, i) { |
|
role = policydb->role_val_to_struct[i]; |
|
usercon.role = i + 1; |
|
ebitmap_for_each_positive_bit(&role->types, tnode, j) { |
|
usercon.type = j + 1; |
|
|
|
if (mls_setup_user_range(policydb, fromcon, user, |
|
&usercon)) |
|
continue; |
|
|
|
rc = sidtab_context_to_sid(sidtab, &usercon, &sid); |
|
if (rc == -ESTALE) { |
|
rcu_read_unlock(); |
|
goto retry; |
|
} |
|
if (rc) |
|
goto out_unlock; |
|
if (mynel < maxnel) { |
|
mysids[mynel++] = sid; |
|
} else { |
|
rc = -ENOMEM; |
|
maxnel += SIDS_NEL; |
|
mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); |
|
if (!mysids2) |
|
goto out_unlock; |
|
memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); |
|
kfree(mysids); |
|
mysids = mysids2; |
|
mysids[mynel++] = sid; |
|
} |
|
} |
|
} |
|
rc = 0; |
|
out_unlock: |
|
rcu_read_unlock(); |
|
if (rc || !mynel) { |
|
kfree(mysids); |
|
return rc; |
|
} |
|
|
|
rc = -ENOMEM; |
|
mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL); |
|
if (!mysids2) { |
|
kfree(mysids); |
|
return rc; |
|
} |
|
for (i = 0, j = 0; i < mynel; i++) { |
|
struct av_decision dummy_avd; |
|
rc = avc_has_perm_noaudit(state, |
|
fromsid, mysids[i], |
|
SECCLASS_PROCESS, /* kernel value */ |
|
PROCESS__TRANSITION, AVC_STRICT, |
|
&dummy_avd); |
|
if (!rc) |
|
mysids2[j++] = mysids[i]; |
|
cond_resched(); |
|
} |
|
kfree(mysids); |
|
*sids = mysids2; |
|
*nel = j; |
|
return 0; |
|
} |
|
|
|
/** |
|
* __security_genfs_sid - Helper to obtain a SID for a file in a filesystem |
|
* @fstype: filesystem type |
|
* @path: path from root of mount |
|
* @sclass: file security class |
|
* @sid: SID for path |
|
* |
|
* Obtain a SID to use for a file in a filesystem that |
|
* cannot support xattr or use a fixed labeling behavior like |
|
* transition SIDs or task SIDs. |
|
* |
|
* WARNING: This function may return -ESTALE, indicating that the caller |
|
* must retry the operation after re-acquiring the policy pointer! |
|
*/ |
|
static inline int __security_genfs_sid(struct selinux_policy *policy, |
|
const char *fstype, |
|
char *path, |
|
u16 orig_sclass, |
|
u32 *sid) |
|
{ |
|
struct policydb *policydb = &policy->policydb; |
|
struct sidtab *sidtab = policy->sidtab; |
|
int len; |
|
u16 sclass; |
|
struct genfs *genfs; |
|
struct ocontext *c; |
|
int rc, cmp = 0; |
|
|
|
while (path[0] == '/' && path[1] == '/') |
|
path++; |
|
|
|
sclass = unmap_class(&policy->map, orig_sclass); |
|
*sid = SECINITSID_UNLABELED; |
|
|
|
for (genfs = policydb->genfs; genfs; genfs = genfs->next) { |
|
cmp = strcmp(fstype, genfs->fstype); |
|
if (cmp <= 0) |
|
break; |
|
} |
|
|
|
rc = -ENOENT; |
|
if (!genfs || cmp) |
|
goto out; |
|
|
|
for (c = genfs->head; c; c = c->next) { |
|
len = strlen(c->u.name); |
|
if ((!c->v.sclass || sclass == c->v.sclass) && |
|
(strncmp(c->u.name, path, len) == 0)) |
|
break; |
|
} |
|
|
|
rc = -ENOENT; |
|
if (!c) |
|
goto out; |
|
|
|
if (!c->sid[0]) { |
|
rc = sidtab_context_to_sid(sidtab, &c->context[0], &c->sid[0]); |
|
if (rc) |
|
goto out; |
|
} |
|
|
|
*sid = c->sid[0]; |
|
rc = 0; |
|
out: |
|
return rc; |
|
} |
|
|
|
/** |
|
* security_genfs_sid - Obtain a SID for a file in a filesystem |
|
* @fstype: filesystem type |
|
* @path: path from root of mount |
|
* @sclass: file security class |
|
* @sid: SID for path |
|
* |
|
* Acquire policy_rwlock before calling __security_genfs_sid() and release |
|
* it afterward. |
|
*/ |
|
int security_genfs_sid(struct selinux_state *state, |
|
const char *fstype, |
|
char *path, |
|
u16 orig_sclass, |
|
u32 *sid) |
|
{ |
|
struct selinux_policy *policy; |
|
int retval; |
|
|
|
if (!selinux_initialized(state)) { |
|
*sid = SECINITSID_UNLABELED; |
|
return 0; |
|
} |
|
|
|
do { |
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
retval = __security_genfs_sid(policy, fstype, path, |
|
orig_sclass, sid); |
|
rcu_read_unlock(); |
|
} while (retval == -ESTALE); |
|
return retval; |
|
} |
|
|
|
int selinux_policy_genfs_sid(struct selinux_policy *policy, |
|
const char *fstype, |
|
char *path, |
|
u16 orig_sclass, |
|
u32 *sid) |
|
{ |
|
/* no lock required, policy is not yet accessible by other threads */ |
|
return __security_genfs_sid(policy, fstype, path, orig_sclass, sid); |
|
} |
|
|
|
/** |
|
* security_fs_use - Determine how to handle labeling for a filesystem. |
|
* @sb: superblock in question |
|
*/ |
|
int security_fs_use(struct selinux_state *state, struct super_block *sb) |
|
{ |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
struct sidtab *sidtab; |
|
int rc; |
|
struct ocontext *c; |
|
struct superblock_security_struct *sbsec = sb->s_security; |
|
const char *fstype = sb->s_type->name; |
|
|
|
if (!selinux_initialized(state)) { |
|
sbsec->behavior = SECURITY_FS_USE_NONE; |
|
sbsec->sid = SECINITSID_UNLABELED; |
|
return 0; |
|
} |
|
|
|
retry: |
|
rc = 0; |
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
policydb = &policy->policydb; |
|
sidtab = policy->sidtab; |
|
|
|
c = policydb->ocontexts[OCON_FSUSE]; |
|
while (c) { |
|
if (strcmp(fstype, c->u.name) == 0) |
|
break; |
|
c = c->next; |
|
} |
|
|
|
if (c) { |
|
sbsec->behavior = c->v.behavior; |
|
if (!c->sid[0]) { |
|
rc = sidtab_context_to_sid(sidtab, &c->context[0], |
|
&c->sid[0]); |
|
if (rc == -ESTALE) { |
|
rcu_read_unlock(); |
|
goto retry; |
|
} |
|
if (rc) |
|
goto out; |
|
} |
|
sbsec->sid = c->sid[0]; |
|
} else { |
|
rc = __security_genfs_sid(policy, fstype, "/", |
|
SECCLASS_DIR, &sbsec->sid); |
|
if (rc == -ESTALE) { |
|
rcu_read_unlock(); |
|
goto retry; |
|
} |
|
if (rc) { |
|
sbsec->behavior = SECURITY_FS_USE_NONE; |
|
rc = 0; |
|
} else { |
|
sbsec->behavior = SECURITY_FS_USE_GENFS; |
|
} |
|
} |
|
|
|
out: |
|
rcu_read_unlock(); |
|
return rc; |
|
} |
|
|
|
int security_get_bools(struct selinux_policy *policy, |
|
u32 *len, char ***names, int **values) |
|
{ |
|
struct policydb *policydb; |
|
u32 i; |
|
int rc; |
|
|
|
policydb = &policy->policydb; |
|
|
|
*names = NULL; |
|
*values = NULL; |
|
|
|
rc = 0; |
|
*len = policydb->p_bools.nprim; |
|
if (!*len) |
|
goto out; |
|
|
|
rc = -ENOMEM; |
|
*names = kcalloc(*len, sizeof(char *), GFP_ATOMIC); |
|
if (!*names) |
|
goto err; |
|
|
|
rc = -ENOMEM; |
|
*values = kcalloc(*len, sizeof(int), GFP_ATOMIC); |
|
if (!*values) |
|
goto err; |
|
|
|
for (i = 0; i < *len; i++) { |
|
(*values)[i] = policydb->bool_val_to_struct[i]->state; |
|
|
|
rc = -ENOMEM; |
|
(*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i), |
|
GFP_ATOMIC); |
|
if (!(*names)[i]) |
|
goto err; |
|
} |
|
rc = 0; |
|
out: |
|
return rc; |
|
err: |
|
if (*names) { |
|
for (i = 0; i < *len; i++) |
|
kfree((*names)[i]); |
|
kfree(*names); |
|
} |
|
kfree(*values); |
|
*len = 0; |
|
*names = NULL; |
|
*values = NULL; |
|
goto out; |
|
} |
|
|
|
|
|
int security_set_bools(struct selinux_state *state, u32 len, int *values) |
|
{ |
|
struct selinux_policy *newpolicy, *oldpolicy; |
|
int rc; |
|
u32 i, seqno = 0; |
|
|
|
if (!selinux_initialized(state)) |
|
return -EINVAL; |
|
|
|
oldpolicy = rcu_dereference_protected(state->policy, |
|
lockdep_is_held(&state->policy_mutex)); |
|
|
|
/* Consistency check on number of booleans, should never fail */ |
|
if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim)) |
|
return -EINVAL; |
|
|
|
newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL); |
|
if (!newpolicy) |
|
return -ENOMEM; |
|
|
|
/* |
|
* Deep copy only the parts of the policydb that might be |
|
* modified as a result of changing booleans. |
|
*/ |
|
rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb); |
|
if (rc) { |
|
kfree(newpolicy); |
|
return -ENOMEM; |
|
} |
|
|
|
/* Update the boolean states in the copy */ |
|
for (i = 0; i < len; i++) { |
|
int new_state = !!values[i]; |
|
int old_state = newpolicy->policydb.bool_val_to_struct[i]->state; |
|
|
|
if (new_state != old_state) { |
|
audit_log(audit_context(), GFP_ATOMIC, |
|
AUDIT_MAC_CONFIG_CHANGE, |
|
"bool=%s val=%d old_val=%d auid=%u ses=%u", |
|
sym_name(&newpolicy->policydb, SYM_BOOLS, i), |
|
new_state, |
|
old_state, |
|
from_kuid(&init_user_ns, audit_get_loginuid(current)), |
|
audit_get_sessionid(current)); |
|
newpolicy->policydb.bool_val_to_struct[i]->state = new_state; |
|
} |
|
} |
|
|
|
/* Re-evaluate the conditional rules in the copy */ |
|
evaluate_cond_nodes(&newpolicy->policydb); |
|
|
|
/* Set latest granting seqno for new policy */ |
|
newpolicy->latest_granting = oldpolicy->latest_granting + 1; |
|
seqno = newpolicy->latest_granting; |
|
|
|
/* Install the new policy */ |
|
rcu_assign_pointer(state->policy, newpolicy); |
|
|
|
/* |
|
* Free the conditional portions of the old policydb |
|
* that were copied for the new policy, and the oldpolicy |
|
* structure itself but not what it references. |
|
*/ |
|
synchronize_rcu(); |
|
selinux_policy_cond_free(oldpolicy); |
|
|
|
/* Notify others of the policy change */ |
|
selinux_notify_policy_change(state, seqno); |
|
return 0; |
|
} |
|
|
|
int security_get_bool_value(struct selinux_state *state, |
|
u32 index) |
|
{ |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
int rc; |
|
u32 len; |
|
|
|
if (!selinux_initialized(state)) |
|
return 0; |
|
|
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
policydb = &policy->policydb; |
|
|
|
rc = -EFAULT; |
|
len = policydb->p_bools.nprim; |
|
if (index >= len) |
|
goto out; |
|
|
|
rc = policydb->bool_val_to_struct[index]->state; |
|
out: |
|
rcu_read_unlock(); |
|
return rc; |
|
} |
|
|
|
static int security_preserve_bools(struct selinux_policy *oldpolicy, |
|
struct selinux_policy *newpolicy) |
|
{ |
|
int rc, *bvalues = NULL; |
|
char **bnames = NULL; |
|
struct cond_bool_datum *booldatum; |
|
u32 i, nbools = 0; |
|
|
|
rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues); |
|
if (rc) |
|
goto out; |
|
for (i = 0; i < nbools; i++) { |
|
booldatum = symtab_search(&newpolicy->policydb.p_bools, |
|
bnames[i]); |
|
if (booldatum) |
|
booldatum->state = bvalues[i]; |
|
} |
|
evaluate_cond_nodes(&newpolicy->policydb); |
|
|
|
out: |
|
if (bnames) { |
|
for (i = 0; i < nbools; i++) |
|
kfree(bnames[i]); |
|
} |
|
kfree(bnames); |
|
kfree(bvalues); |
|
return rc; |
|
} |
|
|
|
/* |
|
* security_sid_mls_copy() - computes a new sid based on the given |
|
* sid and the mls portion of mls_sid. |
|
*/ |
|
int security_sid_mls_copy(struct selinux_state *state, |
|
u32 sid, u32 mls_sid, u32 *new_sid) |
|
{ |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
struct sidtab *sidtab; |
|
struct context *context1; |
|
struct context *context2; |
|
struct context newcon; |
|
char *s; |
|
u32 len; |
|
int rc; |
|
|
|
if (!selinux_initialized(state)) { |
|
*new_sid = sid; |
|
return 0; |
|
} |
|
|
|
retry: |
|
rc = 0; |
|
context_init(&newcon); |
|
|
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
policydb = &policy->policydb; |
|
sidtab = policy->sidtab; |
|
|
|
if (!policydb->mls_enabled) { |
|
*new_sid = sid; |
|
goto out_unlock; |
|
} |
|
|
|
rc = -EINVAL; |
|
context1 = sidtab_search(sidtab, sid); |
|
if (!context1) { |
|
pr_err("SELinux: %s: unrecognized SID %d\n", |
|
__func__, sid); |
|
goto out_unlock; |
|
} |
|
|
|
rc = -EINVAL; |
|
context2 = sidtab_search(sidtab, mls_sid); |
|
if (!context2) { |
|
pr_err("SELinux: %s: unrecognized SID %d\n", |
|
__func__, mls_sid); |
|
goto out_unlock; |
|
} |
|
|
|
newcon.user = context1->user; |
|
newcon.role = context1->role; |
|
newcon.type = context1->type; |
|
rc = mls_context_cpy(&newcon, context2); |
|
if (rc) |
|
goto out_unlock; |
|
|
|
/* Check the validity of the new context. */ |
|
if (!policydb_context_isvalid(policydb, &newcon)) { |
|
rc = convert_context_handle_invalid_context(state, policydb, |
|
&newcon); |
|
if (rc) { |
|
if (!context_struct_to_string(policydb, &newcon, &s, |
|
&len)) { |
|
struct audit_buffer *ab; |
|
|
|
ab = audit_log_start(audit_context(), |
|
GFP_ATOMIC, |
|
AUDIT_SELINUX_ERR); |
|
audit_log_format(ab, |
|
"op=security_sid_mls_copy invalid_context="); |
|
/* don't record NUL with untrusted strings */ |
|
audit_log_n_untrustedstring(ab, s, len - 1); |
|
audit_log_end(ab); |
|
kfree(s); |
|
} |
|
goto out_unlock; |
|
} |
|
} |
|
rc = sidtab_context_to_sid(sidtab, &newcon, new_sid); |
|
if (rc == -ESTALE) { |
|
rcu_read_unlock(); |
|
context_destroy(&newcon); |
|
goto retry; |
|
} |
|
out_unlock: |
|
rcu_read_unlock(); |
|
context_destroy(&newcon); |
|
return rc; |
|
} |
|
|
|
/** |
|
* security_net_peersid_resolve - Compare and resolve two network peer SIDs |
|
* @nlbl_sid: NetLabel SID |
|
* @nlbl_type: NetLabel labeling protocol type |
|
* @xfrm_sid: XFRM SID |
|
* |
|
* Description: |
|
* Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be |
|
* resolved into a single SID it is returned via @peer_sid and the function |
|
* returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function |
|
* returns a negative value. A table summarizing the behavior is below: |
|
* |
|
* | function return | @sid |
|
* ------------------------------+-----------------+----------------- |
|
* no peer labels | 0 | SECSID_NULL |
|
* single peer label | 0 | <peer_label> |
|
* multiple, consistent labels | 0 | <peer_label> |
|
* multiple, inconsistent labels | -<errno> | SECSID_NULL |
|
* |
|
*/ |
|
int security_net_peersid_resolve(struct selinux_state *state, |
|
u32 nlbl_sid, u32 nlbl_type, |
|
u32 xfrm_sid, |
|
u32 *peer_sid) |
|
{ |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
struct sidtab *sidtab; |
|
int rc; |
|
struct context *nlbl_ctx; |
|
struct context *xfrm_ctx; |
|
|
|
*peer_sid = SECSID_NULL; |
|
|
|
/* handle the common (which also happens to be the set of easy) cases |
|
* right away, these two if statements catch everything involving a |
|
* single or absent peer SID/label */ |
|
if (xfrm_sid == SECSID_NULL) { |
|
*peer_sid = nlbl_sid; |
|
return 0; |
|
} |
|
/* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label |
|
* and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label |
|
* is present */ |
|
if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { |
|
*peer_sid = xfrm_sid; |
|
return 0; |
|
} |
|
|
|
if (!selinux_initialized(state)) |
|
return 0; |
|
|
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
policydb = &policy->policydb; |
|
sidtab = policy->sidtab; |
|
|
|
/* |
|
* We don't need to check initialized here since the only way both |
|
* nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the |
|
* security server was initialized and state->initialized was true. |
|
*/ |
|
if (!policydb->mls_enabled) { |
|
rc = 0; |
|
goto out; |
|
} |
|
|
|
rc = -EINVAL; |
|
nlbl_ctx = sidtab_search(sidtab, nlbl_sid); |
|
if (!nlbl_ctx) { |
|
pr_err("SELinux: %s: unrecognized SID %d\n", |
|
__func__, nlbl_sid); |
|
goto out; |
|
} |
|
rc = -EINVAL; |
|
xfrm_ctx = sidtab_search(sidtab, xfrm_sid); |
|
if (!xfrm_ctx) { |
|
pr_err("SELinux: %s: unrecognized SID %d\n", |
|
__func__, xfrm_sid); |
|
goto out; |
|
} |
|
rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); |
|
if (rc) |
|
goto out; |
|
|
|
/* at present NetLabel SIDs/labels really only carry MLS |
|
* information so if the MLS portion of the NetLabel SID |
|
* matches the MLS portion of the labeled XFRM SID/label |
|
* then pass along the XFRM SID as it is the most |
|
* expressive */ |
|
*peer_sid = xfrm_sid; |
|
out: |
|
rcu_read_unlock(); |
|
return rc; |
|
} |
|
|
|
static int get_classes_callback(void *k, void *d, void *args) |
|
{ |
|
struct class_datum *datum = d; |
|
char *name = k, **classes = args; |
|
int value = datum->value - 1; |
|
|
|
classes[value] = kstrdup(name, GFP_ATOMIC); |
|
if (!classes[value]) |
|
return -ENOMEM; |
|
|
|
return 0; |
|
} |
|
|
|
int security_get_classes(struct selinux_policy *policy, |
|
char ***classes, int *nclasses) |
|
{ |
|
struct policydb *policydb; |
|
int rc; |
|
|
|
policydb = &policy->policydb; |
|
|
|
rc = -ENOMEM; |
|
*nclasses = policydb->p_classes.nprim; |
|
*classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC); |
|
if (!*classes) |
|
goto out; |
|
|
|
rc = hashtab_map(&policydb->p_classes.table, get_classes_callback, |
|
*classes); |
|
if (rc) { |
|
int i; |
|
for (i = 0; i < *nclasses; i++) |
|
kfree((*classes)[i]); |
|
kfree(*classes); |
|
} |
|
|
|
out: |
|
return rc; |
|
} |
|
|
|
static int get_permissions_callback(void *k, void *d, void *args) |
|
{ |
|
struct perm_datum *datum = d; |
|
char *name = k, **perms = args; |
|
int value = datum->value - 1; |
|
|
|
perms[value] = kstrdup(name, GFP_ATOMIC); |
|
if (!perms[value]) |
|
return -ENOMEM; |
|
|
|
return 0; |
|
} |
|
|
|
int security_get_permissions(struct selinux_policy *policy, |
|
char *class, char ***perms, int *nperms) |
|
{ |
|
struct policydb *policydb; |
|
int rc, i; |
|
struct class_datum *match; |
|
|
|
policydb = &policy->policydb; |
|
|
|
rc = -EINVAL; |
|
match = symtab_search(&policydb->p_classes, class); |
|
if (!match) { |
|
pr_err("SELinux: %s: unrecognized class %s\n", |
|
__func__, class); |
|
goto out; |
|
} |
|
|
|
rc = -ENOMEM; |
|
*nperms = match->permissions.nprim; |
|
*perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC); |
|
if (!*perms) |
|
goto out; |
|
|
|
if (match->comdatum) { |
|
rc = hashtab_map(&match->comdatum->permissions.table, |
|
get_permissions_callback, *perms); |
|
if (rc) |
|
goto err; |
|
} |
|
|
|
rc = hashtab_map(&match->permissions.table, get_permissions_callback, |
|
*perms); |
|
if (rc) |
|
goto err; |
|
|
|
out: |
|
return rc; |
|
|
|
err: |
|
for (i = 0; i < *nperms; i++) |
|
kfree((*perms)[i]); |
|
kfree(*perms); |
|
return rc; |
|
} |
|
|
|
int security_get_reject_unknown(struct selinux_state *state) |
|
{ |
|
struct selinux_policy *policy; |
|
int value; |
|
|
|
if (!selinux_initialized(state)) |
|
return 0; |
|
|
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
value = policy->policydb.reject_unknown; |
|
rcu_read_unlock(); |
|
return value; |
|
} |
|
|
|
int security_get_allow_unknown(struct selinux_state *state) |
|
{ |
|
struct selinux_policy *policy; |
|
int value; |
|
|
|
if (!selinux_initialized(state)) |
|
return 0; |
|
|
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
value = policy->policydb.allow_unknown; |
|
rcu_read_unlock(); |
|
return value; |
|
} |
|
|
|
/** |
|
* security_policycap_supported - Check for a specific policy capability |
|
* @req_cap: capability |
|
* |
|
* Description: |
|
* This function queries the currently loaded policy to see if it supports the |
|
* capability specified by @req_cap. Returns true (1) if the capability is |
|
* supported, false (0) if it isn't supported. |
|
* |
|
*/ |
|
int security_policycap_supported(struct selinux_state *state, |
|
unsigned int req_cap) |
|
{ |
|
struct selinux_policy *policy; |
|
int rc; |
|
|
|
if (!selinux_initialized(state)) |
|
return 0; |
|
|
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap); |
|
rcu_read_unlock(); |
|
|
|
return rc; |
|
} |
|
|
|
struct selinux_audit_rule { |
|
u32 au_seqno; |
|
struct context au_ctxt; |
|
}; |
|
|
|
void selinux_audit_rule_free(void *vrule) |
|
{ |
|
struct selinux_audit_rule *rule = vrule; |
|
|
|
if (rule) { |
|
context_destroy(&rule->au_ctxt); |
|
kfree(rule); |
|
} |
|
} |
|
|
|
int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) |
|
{ |
|
struct selinux_state *state = &selinux_state; |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
struct selinux_audit_rule *tmprule; |
|
struct role_datum *roledatum; |
|
struct type_datum *typedatum; |
|
struct user_datum *userdatum; |
|
struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; |
|
int rc = 0; |
|
|
|
*rule = NULL; |
|
|
|
if (!selinux_initialized(state)) |
|
return -EOPNOTSUPP; |
|
|
|
switch (field) { |
|
case AUDIT_SUBJ_USER: |
|
case AUDIT_SUBJ_ROLE: |
|
case AUDIT_SUBJ_TYPE: |
|
case AUDIT_OBJ_USER: |
|
case AUDIT_OBJ_ROLE: |
|
case AUDIT_OBJ_TYPE: |
|
/* only 'equals' and 'not equals' fit user, role, and type */ |
|
if (op != Audit_equal && op != Audit_not_equal) |
|
return -EINVAL; |
|
break; |
|
case AUDIT_SUBJ_SEN: |
|
case AUDIT_SUBJ_CLR: |
|
case AUDIT_OBJ_LEV_LOW: |
|
case AUDIT_OBJ_LEV_HIGH: |
|
/* we do not allow a range, indicated by the presence of '-' */ |
|
if (strchr(rulestr, '-')) |
|
return -EINVAL; |
|
break; |
|
default: |
|
/* only the above fields are valid */ |
|
return -EINVAL; |
|
} |
|
|
|
tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL); |
|
if (!tmprule) |
|
return -ENOMEM; |
|
|
|
context_init(&tmprule->au_ctxt); |
|
|
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
policydb = &policy->policydb; |
|
|
|
tmprule->au_seqno = policy->latest_granting; |
|
|
|
switch (field) { |
|
case AUDIT_SUBJ_USER: |
|
case AUDIT_OBJ_USER: |
|
rc = -EINVAL; |
|
userdatum = symtab_search(&policydb->p_users, rulestr); |
|
if (!userdatum) |
|
goto out; |
|
tmprule->au_ctxt.user = userdatum->value; |
|
break; |
|
case AUDIT_SUBJ_ROLE: |
|
case AUDIT_OBJ_ROLE: |
|
rc = -EINVAL; |
|
roledatum = symtab_search(&policydb->p_roles, rulestr); |
|
if (!roledatum) |
|
goto out; |
|
tmprule->au_ctxt.role = roledatum->value; |
|
break; |
|
case AUDIT_SUBJ_TYPE: |
|
case AUDIT_OBJ_TYPE: |
|
rc = -EINVAL; |
|
typedatum = symtab_search(&policydb->p_types, rulestr); |
|
if (!typedatum) |
|
goto out; |
|
tmprule->au_ctxt.type = typedatum->value; |
|
break; |
|
case AUDIT_SUBJ_SEN: |
|
case AUDIT_SUBJ_CLR: |
|
case AUDIT_OBJ_LEV_LOW: |
|
case AUDIT_OBJ_LEV_HIGH: |
|
rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt, |
|
GFP_ATOMIC); |
|
if (rc) |
|
goto out; |
|
break; |
|
} |
|
rc = 0; |
|
out: |
|
rcu_read_unlock(); |
|
|
|
if (rc) { |
|
selinux_audit_rule_free(tmprule); |
|
tmprule = NULL; |
|
} |
|
|
|
*rule = tmprule; |
|
|
|
return rc; |
|
} |
|
|
|
/* Check to see if the rule contains any selinux fields */ |
|
int selinux_audit_rule_known(struct audit_krule *rule) |
|
{ |
|
int i; |
|
|
|
for (i = 0; i < rule->field_count; i++) { |
|
struct audit_field *f = &rule->fields[i]; |
|
switch (f->type) { |
|
case AUDIT_SUBJ_USER: |
|
case AUDIT_SUBJ_ROLE: |
|
case AUDIT_SUBJ_TYPE: |
|
case AUDIT_SUBJ_SEN: |
|
case AUDIT_SUBJ_CLR: |
|
case AUDIT_OBJ_USER: |
|
case AUDIT_OBJ_ROLE: |
|
case AUDIT_OBJ_TYPE: |
|
case AUDIT_OBJ_LEV_LOW: |
|
case AUDIT_OBJ_LEV_HIGH: |
|
return 1; |
|
} |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule) |
|
{ |
|
struct selinux_state *state = &selinux_state; |
|
struct selinux_policy *policy; |
|
struct context *ctxt; |
|
struct mls_level *level; |
|
struct selinux_audit_rule *rule = vrule; |
|
int match = 0; |
|
|
|
if (unlikely(!rule)) { |
|
WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n"); |
|
return -ENOENT; |
|
} |
|
|
|
if (!selinux_initialized(state)) |
|
return 0; |
|
|
|
rcu_read_lock(); |
|
|
|
policy = rcu_dereference(state->policy); |
|
|
|
if (rule->au_seqno < policy->latest_granting) { |
|
match = -ESTALE; |
|
goto out; |
|
} |
|
|
|
ctxt = sidtab_search(policy->sidtab, sid); |
|
if (unlikely(!ctxt)) { |
|
WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n", |
|
sid); |
|
match = -ENOENT; |
|
goto out; |
|
} |
|
|
|
/* a field/op pair that is not caught here will simply fall through |
|
without a match */ |
|
switch (field) { |
|
case AUDIT_SUBJ_USER: |
|
case AUDIT_OBJ_USER: |
|
switch (op) { |
|
case Audit_equal: |
|
match = (ctxt->user == rule->au_ctxt.user); |
|
break; |
|
case Audit_not_equal: |
|
match = (ctxt->user != rule->au_ctxt.user); |
|
break; |
|
} |
|
break; |
|
case AUDIT_SUBJ_ROLE: |
|
case AUDIT_OBJ_ROLE: |
|
switch (op) { |
|
case Audit_equal: |
|
match = (ctxt->role == rule->au_ctxt.role); |
|
break; |
|
case Audit_not_equal: |
|
match = (ctxt->role != rule->au_ctxt.role); |
|
break; |
|
} |
|
break; |
|
case AUDIT_SUBJ_TYPE: |
|
case AUDIT_OBJ_TYPE: |
|
switch (op) { |
|
case Audit_equal: |
|
match = (ctxt->type == rule->au_ctxt.type); |
|
break; |
|
case Audit_not_equal: |
|
match = (ctxt->type != rule->au_ctxt.type); |
|
break; |
|
} |
|
break; |
|
case AUDIT_SUBJ_SEN: |
|
case AUDIT_SUBJ_CLR: |
|
case AUDIT_OBJ_LEV_LOW: |
|
case AUDIT_OBJ_LEV_HIGH: |
|
level = ((field == AUDIT_SUBJ_SEN || |
|
field == AUDIT_OBJ_LEV_LOW) ? |
|
&ctxt->range.level[0] : &ctxt->range.level[1]); |
|
switch (op) { |
|
case Audit_equal: |
|
match = mls_level_eq(&rule->au_ctxt.range.level[0], |
|
level); |
|
break; |
|
case Audit_not_equal: |
|
match = !mls_level_eq(&rule->au_ctxt.range.level[0], |
|
level); |
|
break; |
|
case Audit_lt: |
|
match = (mls_level_dom(&rule->au_ctxt.range.level[0], |
|
level) && |
|
!mls_level_eq(&rule->au_ctxt.range.level[0], |
|
level)); |
|
break; |
|
case Audit_le: |
|
match = mls_level_dom(&rule->au_ctxt.range.level[0], |
|
level); |
|
break; |
|
case Audit_gt: |
|
match = (mls_level_dom(level, |
|
&rule->au_ctxt.range.level[0]) && |
|
!mls_level_eq(level, |
|
&rule->au_ctxt.range.level[0])); |
|
break; |
|
case Audit_ge: |
|
match = mls_level_dom(level, |
|
&rule->au_ctxt.range.level[0]); |
|
break; |
|
} |
|
} |
|
|
|
out: |
|
rcu_read_unlock(); |
|
return match; |
|
} |
|
|
|
static int aurule_avc_callback(u32 event) |
|
{ |
|
if (event == AVC_CALLBACK_RESET) |
|
return audit_update_lsm_rules(); |
|
return 0; |
|
} |
|
|
|
static int __init aurule_init(void) |
|
{ |
|
int err; |
|
|
|
err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET); |
|
if (err) |
|
panic("avc_add_callback() failed, error %d\n", err); |
|
|
|
return err; |
|
} |
|
__initcall(aurule_init); |
|
|
|
#ifdef CONFIG_NETLABEL |
|
/** |
|
* security_netlbl_cache_add - Add an entry to the NetLabel cache |
|
* @secattr: the NetLabel packet security attributes |
|
* @sid: the SELinux SID |
|
* |
|
* Description: |
|
* Attempt to cache the context in @ctx, which was derived from the packet in |
|
* @skb, in the NetLabel subsystem cache. This function assumes @secattr has |
|
* already been initialized. |
|
* |
|
*/ |
|
static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, |
|
u32 sid) |
|
{ |
|
u32 *sid_cache; |
|
|
|
sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC); |
|
if (sid_cache == NULL) |
|
return; |
|
secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); |
|
if (secattr->cache == NULL) { |
|
kfree(sid_cache); |
|
return; |
|
} |
|
|
|
*sid_cache = sid; |
|
secattr->cache->free = kfree; |
|
secattr->cache->data = sid_cache; |
|
secattr->flags |= NETLBL_SECATTR_CACHE; |
|
} |
|
|
|
/** |
|
* security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID |
|
* @secattr: the NetLabel packet security attributes |
|
* @sid: the SELinux SID |
|
* |
|
* Description: |
|
* Convert the given NetLabel security attributes in @secattr into a |
|
* SELinux SID. If the @secattr field does not contain a full SELinux |
|
* SID/context then use SECINITSID_NETMSG as the foundation. If possible the |
|
* 'cache' field of @secattr is set and the CACHE flag is set; this is to |
|
* allow the @secattr to be used by NetLabel to cache the secattr to SID |
|
* conversion for future lookups. Returns zero on success, negative values on |
|
* failure. |
|
* |
|
*/ |
|
int security_netlbl_secattr_to_sid(struct selinux_state *state, |
|
struct netlbl_lsm_secattr *secattr, |
|
u32 *sid) |
|
{ |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
struct sidtab *sidtab; |
|
int rc; |
|
struct context *ctx; |
|
struct context ctx_new; |
|
|
|
if (!selinux_initialized(state)) { |
|
*sid = SECSID_NULL; |
|
return 0; |
|
} |
|
|
|
retry: |
|
rc = 0; |
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
policydb = &policy->policydb; |
|
sidtab = policy->sidtab; |
|
|
|
if (secattr->flags & NETLBL_SECATTR_CACHE) |
|
*sid = *(u32 *)secattr->cache->data; |
|
else if (secattr->flags & NETLBL_SECATTR_SECID) |
|
*sid = secattr->attr.secid; |
|
else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { |
|
rc = -EIDRM; |
|
ctx = sidtab_search(sidtab, SECINITSID_NETMSG); |
|
if (ctx == NULL) |
|
goto out; |
|
|
|
context_init(&ctx_new); |
|
ctx_new.user = ctx->user; |
|
ctx_new.role = ctx->role; |
|
ctx_new.type = ctx->type; |
|
mls_import_netlbl_lvl(policydb, &ctx_new, secattr); |
|
if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { |
|
rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr); |
|
if (rc) |
|
goto out; |
|
} |
|
rc = -EIDRM; |
|
if (!mls_context_isvalid(policydb, &ctx_new)) { |
|
ebitmap_destroy(&ctx_new.range.level[0].cat); |
|
goto out; |
|
} |
|
|
|
rc = sidtab_context_to_sid(sidtab, &ctx_new, sid); |
|
ebitmap_destroy(&ctx_new.range.level[0].cat); |
|
if (rc == -ESTALE) { |
|
rcu_read_unlock(); |
|
goto retry; |
|
} |
|
if (rc) |
|
goto out; |
|
|
|
security_netlbl_cache_add(secattr, *sid); |
|
} else |
|
*sid = SECSID_NULL; |
|
|
|
out: |
|
rcu_read_unlock(); |
|
return rc; |
|
} |
|
|
|
/** |
|
* security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr |
|
* @sid: the SELinux SID |
|
* @secattr: the NetLabel packet security attributes |
|
* |
|
* Description: |
|
* Convert the given SELinux SID in @sid into a NetLabel security attribute. |
|
* Returns zero on success, negative values on failure. |
|
* |
|
*/ |
|
int security_netlbl_sid_to_secattr(struct selinux_state *state, |
|
u32 sid, struct netlbl_lsm_secattr *secattr) |
|
{ |
|
struct selinux_policy *policy; |
|
struct policydb *policydb; |
|
int rc; |
|
struct context *ctx; |
|
|
|
if (!selinux_initialized(state)) |
|
return 0; |
|
|
|
rcu_read_lock(); |
|
policy = rcu_dereference(state->policy); |
|
policydb = &policy->policydb; |
|
|
|
rc = -ENOENT; |
|
ctx = sidtab_search(policy->sidtab, sid); |
|
if (ctx == NULL) |
|
goto out; |
|
|
|
rc = -ENOMEM; |
|
secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1), |
|
GFP_ATOMIC); |
|
if (secattr->domain == NULL) |
|
goto out; |
|
|
|
secattr->attr.secid = sid; |
|
secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; |
|
mls_export_netlbl_lvl(policydb, ctx, secattr); |
|
rc = mls_export_netlbl_cat(policydb, ctx, secattr); |
|
out: |
|
rcu_read_unlock(); |
|
return rc; |
|
} |
|
#endif /* CONFIG_NETLABEL */ |
|
|
|
/** |
|
* __security_read_policy - read the policy. |
|
* @policy: SELinux policy |
|
* @data: binary policy data |
|
* @len: length of data in bytes |
|
* |
|
*/ |
|
static int __security_read_policy(struct selinux_policy *policy, |
|
void *data, size_t *len) |
|
{ |
|
int rc; |
|
struct policy_file fp; |
|
|
|
fp.data = data; |
|
fp.len = *len; |
|
|
|
rc = policydb_write(&policy->policydb, &fp); |
|
if (rc) |
|
return rc; |
|
|
|
*len = (unsigned long)fp.data - (unsigned long)data; |
|
return 0; |
|
} |
|
|
|
/** |
|
* security_read_policy - read the policy. |
|
* @state: selinux_state |
|
* @data: binary policy data |
|
* @len: length of data in bytes |
|
* |
|
*/ |
|
int security_read_policy(struct selinux_state *state, |
|
void **data, size_t *len) |
|
{ |
|
struct selinux_policy *policy; |
|
|
|
policy = rcu_dereference_protected( |
|
state->policy, lockdep_is_held(&state->policy_mutex)); |
|
if (!policy) |
|
return -EINVAL; |
|
|
|
*len = policy->policydb.len; |
|
*data = vmalloc_user(*len); |
|
if (!*data) |
|
return -ENOMEM; |
|
|
|
return __security_read_policy(policy, *data, len); |
|
} |
|
|
|
/** |
|
* security_read_state_kernel - read the policy. |
|
* @state: selinux_state |
|
* @data: binary policy data |
|
* @len: length of data in bytes |
|
* |
|
* Allocates kernel memory for reading SELinux policy. |
|
* This function is for internal use only and should not |
|
* be used for returning data to user space. |
|
* |
|
* This function must be called with policy_mutex held. |
|
*/ |
|
int security_read_state_kernel(struct selinux_state *state, |
|
void **data, size_t *len) |
|
{ |
|
struct selinux_policy *policy; |
|
|
|
policy = rcu_dereference_protected( |
|
state->policy, lockdep_is_held(&state->policy_mutex)); |
|
if (!policy) |
|
return -EINVAL; |
|
|
|
*len = policy->policydb.len; |
|
*data = vmalloc(*len); |
|
if (!*data) |
|
return -ENOMEM; |
|
|
|
return __security_read_policy(policy, *data, len); |
|
}
|
|
|