forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
472 lines
11 KiB
472 lines
11 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* common LSM auditing functions |
|
* |
|
* Based on code written for SELinux by : |
|
* Stephen Smalley, <[email protected]> |
|
* James Morris <[email protected]> |
|
* Author : Etienne Basset, <[email protected]> |
|
*/ |
|
|
|
#include <linux/types.h> |
|
#include <linux/stddef.h> |
|
#include <linux/kernel.h> |
|
#include <linux/gfp.h> |
|
#include <linux/fs.h> |
|
#include <linux/init.h> |
|
#include <net/sock.h> |
|
#include <linux/un.h> |
|
#include <net/af_unix.h> |
|
#include <linux/audit.h> |
|
#include <linux/ipv6.h> |
|
#include <linux/ip.h> |
|
#include <net/ip.h> |
|
#include <net/ipv6.h> |
|
#include <linux/tcp.h> |
|
#include <linux/udp.h> |
|
#include <linux/dccp.h> |
|
#include <linux/sctp.h> |
|
#include <linux/lsm_audit.h> |
|
#include <linux/security.h> |
|
|
|
/** |
|
* ipv4_skb_to_auditdata : fill auditdata from skb |
|
* @skb : the skb |
|
* @ad : the audit data to fill |
|
* @proto : the layer 4 protocol |
|
* |
|
* return 0 on success |
|
*/ |
|
int ipv4_skb_to_auditdata(struct sk_buff *skb, |
|
struct common_audit_data *ad, u8 *proto) |
|
{ |
|
int ret = 0; |
|
struct iphdr *ih; |
|
|
|
ih = ip_hdr(skb); |
|
if (ih == NULL) |
|
return -EINVAL; |
|
|
|
ad->u.net->v4info.saddr = ih->saddr; |
|
ad->u.net->v4info.daddr = ih->daddr; |
|
|
|
if (proto) |
|
*proto = ih->protocol; |
|
/* non initial fragment */ |
|
if (ntohs(ih->frag_off) & IP_OFFSET) |
|
return 0; |
|
|
|
switch (ih->protocol) { |
|
case IPPROTO_TCP: { |
|
struct tcphdr *th = tcp_hdr(skb); |
|
if (th == NULL) |
|
break; |
|
|
|
ad->u.net->sport = th->source; |
|
ad->u.net->dport = th->dest; |
|
break; |
|
} |
|
case IPPROTO_UDP: { |
|
struct udphdr *uh = udp_hdr(skb); |
|
if (uh == NULL) |
|
break; |
|
|
|
ad->u.net->sport = uh->source; |
|
ad->u.net->dport = uh->dest; |
|
break; |
|
} |
|
case IPPROTO_DCCP: { |
|
struct dccp_hdr *dh = dccp_hdr(skb); |
|
if (dh == NULL) |
|
break; |
|
|
|
ad->u.net->sport = dh->dccph_sport; |
|
ad->u.net->dport = dh->dccph_dport; |
|
break; |
|
} |
|
case IPPROTO_SCTP: { |
|
struct sctphdr *sh = sctp_hdr(skb); |
|
if (sh == NULL) |
|
break; |
|
ad->u.net->sport = sh->source; |
|
ad->u.net->dport = sh->dest; |
|
break; |
|
} |
|
default: |
|
ret = -EINVAL; |
|
} |
|
return ret; |
|
} |
|
#if IS_ENABLED(CONFIG_IPV6) |
|
/** |
|
* ipv6_skb_to_auditdata : fill auditdata from skb |
|
* @skb : the skb |
|
* @ad : the audit data to fill |
|
* @proto : the layer 4 protocol |
|
* |
|
* return 0 on success |
|
*/ |
|
int ipv6_skb_to_auditdata(struct sk_buff *skb, |
|
struct common_audit_data *ad, u8 *proto) |
|
{ |
|
int offset, ret = 0; |
|
struct ipv6hdr *ip6; |
|
u8 nexthdr; |
|
__be16 frag_off; |
|
|
|
ip6 = ipv6_hdr(skb); |
|
if (ip6 == NULL) |
|
return -EINVAL; |
|
ad->u.net->v6info.saddr = ip6->saddr; |
|
ad->u.net->v6info.daddr = ip6->daddr; |
|
/* IPv6 can have several extension header before the Transport header |
|
* skip them */ |
|
offset = skb_network_offset(skb); |
|
offset += sizeof(*ip6); |
|
nexthdr = ip6->nexthdr; |
|
offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off); |
|
if (offset < 0) |
|
return 0; |
|
if (proto) |
|
*proto = nexthdr; |
|
switch (nexthdr) { |
|
case IPPROTO_TCP: { |
|
struct tcphdr _tcph, *th; |
|
|
|
th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); |
|
if (th == NULL) |
|
break; |
|
|
|
ad->u.net->sport = th->source; |
|
ad->u.net->dport = th->dest; |
|
break; |
|
} |
|
case IPPROTO_UDP: { |
|
struct udphdr _udph, *uh; |
|
|
|
uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); |
|
if (uh == NULL) |
|
break; |
|
|
|
ad->u.net->sport = uh->source; |
|
ad->u.net->dport = uh->dest; |
|
break; |
|
} |
|
case IPPROTO_DCCP: { |
|
struct dccp_hdr _dccph, *dh; |
|
|
|
dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); |
|
if (dh == NULL) |
|
break; |
|
|
|
ad->u.net->sport = dh->dccph_sport; |
|
ad->u.net->dport = dh->dccph_dport; |
|
break; |
|
} |
|
case IPPROTO_SCTP: { |
|
struct sctphdr _sctph, *sh; |
|
|
|
sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph); |
|
if (sh == NULL) |
|
break; |
|
ad->u.net->sport = sh->source; |
|
ad->u.net->dport = sh->dest; |
|
break; |
|
} |
|
default: |
|
ret = -EINVAL; |
|
} |
|
return ret; |
|
} |
|
#endif |
|
|
|
|
|
static inline void print_ipv6_addr(struct audit_buffer *ab, |
|
const struct in6_addr *addr, __be16 port, |
|
char *name1, char *name2) |
|
{ |
|
if (!ipv6_addr_any(addr)) |
|
audit_log_format(ab, " %s=%pI6c", name1, addr); |
|
if (port) |
|
audit_log_format(ab, " %s=%d", name2, ntohs(port)); |
|
} |
|
|
|
static inline void print_ipv4_addr(struct audit_buffer *ab, __be32 addr, |
|
__be16 port, char *name1, char *name2) |
|
{ |
|
if (addr) |
|
audit_log_format(ab, " %s=%pI4", name1, &addr); |
|
if (port) |
|
audit_log_format(ab, " %s=%d", name2, ntohs(port)); |
|
} |
|
|
|
/** |
|
* dump_common_audit_data - helper to dump common audit data |
|
* @a : common audit data |
|
* |
|
*/ |
|
static void dump_common_audit_data(struct audit_buffer *ab, |
|
struct common_audit_data *a) |
|
{ |
|
char comm[sizeof(current->comm)]; |
|
|
|
/* |
|
* To keep stack sizes in check force programers to notice if they |
|
* start making this union too large! See struct lsm_network_audit |
|
* as an example of how to deal with large data. |
|
*/ |
|
BUILD_BUG_ON(sizeof(a->u) > sizeof(void *)*2); |
|
|
|
audit_log_format(ab, " pid=%d comm=", task_tgid_nr(current)); |
|
audit_log_untrustedstring(ab, memcpy(comm, current->comm, sizeof(comm))); |
|
|
|
switch (a->type) { |
|
case LSM_AUDIT_DATA_NONE: |
|
return; |
|
case LSM_AUDIT_DATA_IPC: |
|
audit_log_format(ab, " key=%d ", a->u.ipc_id); |
|
break; |
|
case LSM_AUDIT_DATA_CAP: |
|
audit_log_format(ab, " capability=%d ", a->u.cap); |
|
break; |
|
case LSM_AUDIT_DATA_PATH: { |
|
struct inode *inode; |
|
|
|
audit_log_d_path(ab, " path=", &a->u.path); |
|
|
|
inode = d_backing_inode(a->u.path.dentry); |
|
if (inode) { |
|
audit_log_format(ab, " dev="); |
|
audit_log_untrustedstring(ab, inode->i_sb->s_id); |
|
audit_log_format(ab, " ino=%lu", inode->i_ino); |
|
} |
|
break; |
|
} |
|
case LSM_AUDIT_DATA_FILE: { |
|
struct inode *inode; |
|
|
|
audit_log_d_path(ab, " path=", &a->u.file->f_path); |
|
|
|
inode = file_inode(a->u.file); |
|
if (inode) { |
|
audit_log_format(ab, " dev="); |
|
audit_log_untrustedstring(ab, inode->i_sb->s_id); |
|
audit_log_format(ab, " ino=%lu", inode->i_ino); |
|
} |
|
break; |
|
} |
|
case LSM_AUDIT_DATA_IOCTL_OP: { |
|
struct inode *inode; |
|
|
|
audit_log_d_path(ab, " path=", &a->u.op->path); |
|
|
|
inode = a->u.op->path.dentry->d_inode; |
|
if (inode) { |
|
audit_log_format(ab, " dev="); |
|
audit_log_untrustedstring(ab, inode->i_sb->s_id); |
|
audit_log_format(ab, " ino=%lu", inode->i_ino); |
|
} |
|
|
|
audit_log_format(ab, " ioctlcmd=0x%hx", a->u.op->cmd); |
|
break; |
|
} |
|
case LSM_AUDIT_DATA_DENTRY: { |
|
struct inode *inode; |
|
|
|
audit_log_format(ab, " name="); |
|
spin_lock(&a->u.dentry->d_lock); |
|
audit_log_untrustedstring(ab, a->u.dentry->d_name.name); |
|
spin_unlock(&a->u.dentry->d_lock); |
|
|
|
inode = d_backing_inode(a->u.dentry); |
|
if (inode) { |
|
audit_log_format(ab, " dev="); |
|
audit_log_untrustedstring(ab, inode->i_sb->s_id); |
|
audit_log_format(ab, " ino=%lu", inode->i_ino); |
|
} |
|
break; |
|
} |
|
case LSM_AUDIT_DATA_INODE: { |
|
struct dentry *dentry; |
|
struct inode *inode; |
|
|
|
rcu_read_lock(); |
|
inode = a->u.inode; |
|
dentry = d_find_alias_rcu(inode); |
|
if (dentry) { |
|
audit_log_format(ab, " name="); |
|
spin_lock(&dentry->d_lock); |
|
audit_log_untrustedstring(ab, dentry->d_name.name); |
|
spin_unlock(&dentry->d_lock); |
|
} |
|
audit_log_format(ab, " dev="); |
|
audit_log_untrustedstring(ab, inode->i_sb->s_id); |
|
audit_log_format(ab, " ino=%lu", inode->i_ino); |
|
rcu_read_unlock(); |
|
break; |
|
} |
|
case LSM_AUDIT_DATA_TASK: { |
|
struct task_struct *tsk = a->u.tsk; |
|
if (tsk) { |
|
pid_t pid = task_tgid_nr(tsk); |
|
if (pid) { |
|
char comm[sizeof(tsk->comm)]; |
|
audit_log_format(ab, " opid=%d ocomm=", pid); |
|
audit_log_untrustedstring(ab, |
|
memcpy(comm, tsk->comm, sizeof(comm))); |
|
} |
|
} |
|
break; |
|
} |
|
case LSM_AUDIT_DATA_NET: |
|
if (a->u.net->sk) { |
|
const struct sock *sk = a->u.net->sk; |
|
struct unix_sock *u; |
|
struct unix_address *addr; |
|
int len = 0; |
|
char *p = NULL; |
|
|
|
switch (sk->sk_family) { |
|
case AF_INET: { |
|
struct inet_sock *inet = inet_sk(sk); |
|
|
|
print_ipv4_addr(ab, inet->inet_rcv_saddr, |
|
inet->inet_sport, |
|
"laddr", "lport"); |
|
print_ipv4_addr(ab, inet->inet_daddr, |
|
inet->inet_dport, |
|
"faddr", "fport"); |
|
break; |
|
} |
|
#if IS_ENABLED(CONFIG_IPV6) |
|
case AF_INET6: { |
|
struct inet_sock *inet = inet_sk(sk); |
|
|
|
print_ipv6_addr(ab, &sk->sk_v6_rcv_saddr, |
|
inet->inet_sport, |
|
"laddr", "lport"); |
|
print_ipv6_addr(ab, &sk->sk_v6_daddr, |
|
inet->inet_dport, |
|
"faddr", "fport"); |
|
break; |
|
} |
|
#endif |
|
case AF_UNIX: |
|
u = unix_sk(sk); |
|
addr = smp_load_acquire(&u->addr); |
|
if (!addr) |
|
break; |
|
if (u->path.dentry) { |
|
audit_log_d_path(ab, " path=", &u->path); |
|
break; |
|
} |
|
len = addr->len-sizeof(short); |
|
p = &addr->name->sun_path[0]; |
|
audit_log_format(ab, " path="); |
|
if (*p) |
|
audit_log_untrustedstring(ab, p); |
|
else |
|
audit_log_n_hex(ab, p, len); |
|
break; |
|
} |
|
} |
|
|
|
switch (a->u.net->family) { |
|
case AF_INET: |
|
print_ipv4_addr(ab, a->u.net->v4info.saddr, |
|
a->u.net->sport, |
|
"saddr", "src"); |
|
print_ipv4_addr(ab, a->u.net->v4info.daddr, |
|
a->u.net->dport, |
|
"daddr", "dest"); |
|
break; |
|
case AF_INET6: |
|
print_ipv6_addr(ab, &a->u.net->v6info.saddr, |
|
a->u.net->sport, |
|
"saddr", "src"); |
|
print_ipv6_addr(ab, &a->u.net->v6info.daddr, |
|
a->u.net->dport, |
|
"daddr", "dest"); |
|
break; |
|
} |
|
if (a->u.net->netif > 0) { |
|
struct net_device *dev; |
|
|
|
/* NOTE: we always use init's namespace */ |
|
dev = dev_get_by_index(&init_net, a->u.net->netif); |
|
if (dev) { |
|
audit_log_format(ab, " netif=%s", dev->name); |
|
dev_put(dev); |
|
} |
|
} |
|
break; |
|
#ifdef CONFIG_KEYS |
|
case LSM_AUDIT_DATA_KEY: |
|
audit_log_format(ab, " key_serial=%u", a->u.key_struct.key); |
|
if (a->u.key_struct.key_desc) { |
|
audit_log_format(ab, " key_desc="); |
|
audit_log_untrustedstring(ab, a->u.key_struct.key_desc); |
|
} |
|
break; |
|
#endif |
|
case LSM_AUDIT_DATA_KMOD: |
|
audit_log_format(ab, " kmod="); |
|
audit_log_untrustedstring(ab, a->u.kmod_name); |
|
break; |
|
case LSM_AUDIT_DATA_IBPKEY: { |
|
struct in6_addr sbn_pfx; |
|
|
|
memset(&sbn_pfx.s6_addr, 0, |
|
sizeof(sbn_pfx.s6_addr)); |
|
memcpy(&sbn_pfx.s6_addr, &a->u.ibpkey->subnet_prefix, |
|
sizeof(a->u.ibpkey->subnet_prefix)); |
|
audit_log_format(ab, " pkey=0x%x subnet_prefix=%pI6c", |
|
a->u.ibpkey->pkey, &sbn_pfx); |
|
break; |
|
} |
|
case LSM_AUDIT_DATA_IBENDPORT: |
|
audit_log_format(ab, " device=%s port_num=%u", |
|
a->u.ibendport->dev_name, |
|
a->u.ibendport->port); |
|
break; |
|
case LSM_AUDIT_DATA_LOCKDOWN: |
|
audit_log_format(ab, " lockdown_reason=\"%s\"", |
|
lockdown_reasons[a->u.reason]); |
|
break; |
|
} /* switch (a->type) */ |
|
} |
|
|
|
/** |
|
* common_lsm_audit - generic LSM auditing function |
|
* @a: auxiliary audit data |
|
* @pre_audit: lsm-specific pre-audit callback |
|
* @post_audit: lsm-specific post-audit callback |
|
* |
|
* setup the audit buffer for common security information |
|
* uses callback to print LSM specific information |
|
*/ |
|
void common_lsm_audit(struct common_audit_data *a, |
|
void (*pre_audit)(struct audit_buffer *, void *), |
|
void (*post_audit)(struct audit_buffer *, void *)) |
|
{ |
|
struct audit_buffer *ab; |
|
|
|
if (a == NULL) |
|
return; |
|
/* we use GFP_ATOMIC so we won't sleep */ |
|
ab = audit_log_start(audit_context(), GFP_ATOMIC | __GFP_NOWARN, |
|
AUDIT_AVC); |
|
|
|
if (ab == NULL) |
|
return; |
|
|
|
if (pre_audit) |
|
pre_audit(ab, a); |
|
|
|
dump_common_audit_data(ab, a); |
|
|
|
if (post_audit) |
|
post_audit(ab, a); |
|
|
|
audit_log_end(ab); |
|
}
|
|
|