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1447 lines
34 KiB
1447 lines
34 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* auditfilter.c -- filtering of audit events |
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* |
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* Copyright 2003-2004 Red Hat, Inc. |
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* Copyright 2005 Hewlett-Packard Development Company, L.P. |
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* Copyright 2005 IBM Corporation |
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*/ |
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|
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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|
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#include <linux/kernel.h> |
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#include <linux/audit.h> |
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#include <linux/kthread.h> |
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#include <linux/mutex.h> |
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#include <linux/fs.h> |
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#include <linux/namei.h> |
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#include <linux/netlink.h> |
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#include <linux/sched.h> |
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#include <linux/slab.h> |
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#include <linux/security.h> |
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#include <net/net_namespace.h> |
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#include <net/sock.h> |
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#include "audit.h" |
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|
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/* |
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* Locking model: |
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* |
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* audit_filter_mutex: |
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* Synchronizes writes and blocking reads of audit's filterlist |
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* data. Rcu is used to traverse the filterlist and access |
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* contents of structs audit_entry, audit_watch and opaque |
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* LSM rules during filtering. If modified, these structures |
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* must be copied and replace their counterparts in the filterlist. |
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* An audit_parent struct is not accessed during filtering, so may |
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* be written directly provided audit_filter_mutex is held. |
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*/ |
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|
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/* Audit filter lists, defined in <linux/audit.h> */ |
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struct list_head audit_filter_list[AUDIT_NR_FILTERS] = { |
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LIST_HEAD_INIT(audit_filter_list[0]), |
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LIST_HEAD_INIT(audit_filter_list[1]), |
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LIST_HEAD_INIT(audit_filter_list[2]), |
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LIST_HEAD_INIT(audit_filter_list[3]), |
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LIST_HEAD_INIT(audit_filter_list[4]), |
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LIST_HEAD_INIT(audit_filter_list[5]), |
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LIST_HEAD_INIT(audit_filter_list[6]), |
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#if AUDIT_NR_FILTERS != 7 |
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#error Fix audit_filter_list initialiser |
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#endif |
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}; |
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static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = { |
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LIST_HEAD_INIT(audit_rules_list[0]), |
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LIST_HEAD_INIT(audit_rules_list[1]), |
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LIST_HEAD_INIT(audit_rules_list[2]), |
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LIST_HEAD_INIT(audit_rules_list[3]), |
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LIST_HEAD_INIT(audit_rules_list[4]), |
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LIST_HEAD_INIT(audit_rules_list[5]), |
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LIST_HEAD_INIT(audit_rules_list[6]), |
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}; |
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|
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DEFINE_MUTEX(audit_filter_mutex); |
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|
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static void audit_free_lsm_field(struct audit_field *f) |
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{ |
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switch (f->type) { |
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case AUDIT_SUBJ_USER: |
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case AUDIT_SUBJ_ROLE: |
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case AUDIT_SUBJ_TYPE: |
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case AUDIT_SUBJ_SEN: |
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case AUDIT_SUBJ_CLR: |
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case AUDIT_OBJ_USER: |
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case AUDIT_OBJ_ROLE: |
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case AUDIT_OBJ_TYPE: |
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case AUDIT_OBJ_LEV_LOW: |
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case AUDIT_OBJ_LEV_HIGH: |
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kfree(f->lsm_str); |
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security_audit_rule_free(f->lsm_rule); |
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} |
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} |
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|
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static inline void audit_free_rule(struct audit_entry *e) |
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{ |
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int i; |
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struct audit_krule *erule = &e->rule; |
|
|
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/* some rules don't have associated watches */ |
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if (erule->watch) |
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audit_put_watch(erule->watch); |
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if (erule->fields) |
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for (i = 0; i < erule->field_count; i++) |
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audit_free_lsm_field(&erule->fields[i]); |
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kfree(erule->fields); |
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kfree(erule->filterkey); |
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kfree(e); |
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} |
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|
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void audit_free_rule_rcu(struct rcu_head *head) |
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{ |
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struct audit_entry *e = container_of(head, struct audit_entry, rcu); |
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audit_free_rule(e); |
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} |
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|
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/* Initialize an audit filterlist entry. */ |
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static inline struct audit_entry *audit_init_entry(u32 field_count) |
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{ |
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struct audit_entry *entry; |
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struct audit_field *fields; |
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|
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entry = kzalloc(sizeof(*entry), GFP_KERNEL); |
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if (unlikely(!entry)) |
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return NULL; |
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|
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fields = kcalloc(field_count, sizeof(*fields), GFP_KERNEL); |
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if (unlikely(!fields)) { |
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kfree(entry); |
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return NULL; |
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} |
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entry->rule.fields = fields; |
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|
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return entry; |
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} |
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|
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/* Unpack a filter field's string representation from user-space |
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* buffer. */ |
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char *audit_unpack_string(void **bufp, size_t *remain, size_t len) |
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{ |
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char *str; |
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|
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if (!*bufp || (len == 0) || (len > *remain)) |
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return ERR_PTR(-EINVAL); |
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|
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/* Of the currently implemented string fields, PATH_MAX |
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* defines the longest valid length. |
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*/ |
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if (len > PATH_MAX) |
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return ERR_PTR(-ENAMETOOLONG); |
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|
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str = kmalloc(len + 1, GFP_KERNEL); |
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if (unlikely(!str)) |
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return ERR_PTR(-ENOMEM); |
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|
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memcpy(str, *bufp, len); |
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str[len] = 0; |
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*bufp += len; |
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*remain -= len; |
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|
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return str; |
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} |
|
|
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/* Translate an inode field to kernel representation. */ |
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static inline int audit_to_inode(struct audit_krule *krule, |
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struct audit_field *f) |
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{ |
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if (krule->listnr != AUDIT_FILTER_EXIT || |
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krule->inode_f || krule->watch || krule->tree || |
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(f->op != Audit_equal && f->op != Audit_not_equal)) |
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return -EINVAL; |
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|
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krule->inode_f = f; |
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return 0; |
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} |
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|
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static __u32 *classes[AUDIT_SYSCALL_CLASSES]; |
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|
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int __init audit_register_class(int class, unsigned *list) |
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{ |
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__u32 *p = kcalloc(AUDIT_BITMASK_SIZE, sizeof(__u32), GFP_KERNEL); |
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if (!p) |
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return -ENOMEM; |
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while (*list != ~0U) { |
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unsigned n = *list++; |
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if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) { |
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kfree(p); |
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return -EINVAL; |
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} |
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p[AUDIT_WORD(n)] |= AUDIT_BIT(n); |
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} |
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if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) { |
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kfree(p); |
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return -EINVAL; |
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} |
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classes[class] = p; |
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return 0; |
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} |
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|
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int audit_match_class(int class, unsigned syscall) |
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{ |
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if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32)) |
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return 0; |
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if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class])) |
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return 0; |
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return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall); |
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} |
|
|
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#ifdef CONFIG_AUDITSYSCALL |
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static inline int audit_match_class_bits(int class, u32 *mask) |
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{ |
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int i; |
|
|
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if (classes[class]) { |
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for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
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if (mask[i] & classes[class][i]) |
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return 0; |
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} |
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return 1; |
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} |
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|
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static int audit_match_signal(struct audit_entry *entry) |
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{ |
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struct audit_field *arch = entry->rule.arch_f; |
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|
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if (!arch) { |
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/* When arch is unspecified, we must check both masks on biarch |
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* as syscall number alone is ambiguous. */ |
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return (audit_match_class_bits(AUDIT_CLASS_SIGNAL, |
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entry->rule.mask) && |
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audit_match_class_bits(AUDIT_CLASS_SIGNAL_32, |
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entry->rule.mask)); |
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} |
|
|
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switch(audit_classify_arch(arch->val)) { |
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case 0: /* native */ |
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return (audit_match_class_bits(AUDIT_CLASS_SIGNAL, |
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entry->rule.mask)); |
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case 1: /* 32bit on biarch */ |
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return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32, |
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entry->rule.mask)); |
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default: |
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return 1; |
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} |
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} |
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#endif |
|
|
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/* Common user-space to kernel rule translation. */ |
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static inline struct audit_entry *audit_to_entry_common(struct audit_rule_data *rule) |
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{ |
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unsigned listnr; |
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struct audit_entry *entry; |
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int i, err; |
|
|
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err = -EINVAL; |
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listnr = rule->flags & ~AUDIT_FILTER_PREPEND; |
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switch(listnr) { |
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default: |
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goto exit_err; |
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#ifdef CONFIG_AUDITSYSCALL |
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case AUDIT_FILTER_ENTRY: |
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pr_err("AUDIT_FILTER_ENTRY is deprecated\n"); |
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goto exit_err; |
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case AUDIT_FILTER_EXIT: |
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case AUDIT_FILTER_TASK: |
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#endif |
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case AUDIT_FILTER_USER: |
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case AUDIT_FILTER_EXCLUDE: |
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case AUDIT_FILTER_FS: |
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; |
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} |
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if (unlikely(rule->action == AUDIT_POSSIBLE)) { |
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pr_err("AUDIT_POSSIBLE is deprecated\n"); |
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goto exit_err; |
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} |
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if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS) |
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goto exit_err; |
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if (rule->field_count > AUDIT_MAX_FIELDS) |
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goto exit_err; |
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|
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err = -ENOMEM; |
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entry = audit_init_entry(rule->field_count); |
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if (!entry) |
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goto exit_err; |
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|
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entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND; |
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entry->rule.listnr = listnr; |
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entry->rule.action = rule->action; |
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entry->rule.field_count = rule->field_count; |
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|
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for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
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entry->rule.mask[i] = rule->mask[i]; |
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|
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for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) { |
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int bit = AUDIT_BITMASK_SIZE * 32 - i - 1; |
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__u32 *p = &entry->rule.mask[AUDIT_WORD(bit)]; |
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__u32 *class; |
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|
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if (!(*p & AUDIT_BIT(bit))) |
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continue; |
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*p &= ~AUDIT_BIT(bit); |
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class = classes[i]; |
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if (class) { |
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int j; |
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for (j = 0; j < AUDIT_BITMASK_SIZE; j++) |
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entry->rule.mask[j] |= class[j]; |
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} |
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} |
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|
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return entry; |
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|
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exit_err: |
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return ERR_PTR(err); |
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} |
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|
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static u32 audit_ops[] = |
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{ |
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[Audit_equal] = AUDIT_EQUAL, |
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[Audit_not_equal] = AUDIT_NOT_EQUAL, |
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[Audit_bitmask] = AUDIT_BIT_MASK, |
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[Audit_bittest] = AUDIT_BIT_TEST, |
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[Audit_lt] = AUDIT_LESS_THAN, |
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[Audit_gt] = AUDIT_GREATER_THAN, |
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[Audit_le] = AUDIT_LESS_THAN_OR_EQUAL, |
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[Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL, |
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}; |
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|
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static u32 audit_to_op(u32 op) |
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{ |
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u32 n; |
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for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++) |
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; |
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return n; |
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} |
|
|
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/* check if an audit field is valid */ |
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static int audit_field_valid(struct audit_entry *entry, struct audit_field *f) |
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{ |
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switch (f->type) { |
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case AUDIT_MSGTYPE: |
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if (entry->rule.listnr != AUDIT_FILTER_EXCLUDE && |
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entry->rule.listnr != AUDIT_FILTER_USER) |
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return -EINVAL; |
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break; |
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case AUDIT_FSTYPE: |
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if (entry->rule.listnr != AUDIT_FILTER_FS) |
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return -EINVAL; |
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break; |
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} |
|
|
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switch (entry->rule.listnr) { |
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case AUDIT_FILTER_FS: |
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switch(f->type) { |
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case AUDIT_FSTYPE: |
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case AUDIT_FILTERKEY: |
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break; |
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default: |
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return -EINVAL; |
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} |
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} |
|
|
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/* Check for valid field type and op */ |
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switch (f->type) { |
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case AUDIT_ARG0: |
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case AUDIT_ARG1: |
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case AUDIT_ARG2: |
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case AUDIT_ARG3: |
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case AUDIT_PERS: /* <uapi/linux/personality.h> */ |
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case AUDIT_DEVMINOR: |
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/* all ops are valid */ |
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break; |
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case AUDIT_UID: |
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case AUDIT_EUID: |
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case AUDIT_SUID: |
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case AUDIT_FSUID: |
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case AUDIT_LOGINUID: |
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case AUDIT_OBJ_UID: |
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case AUDIT_GID: |
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case AUDIT_EGID: |
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case AUDIT_SGID: |
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case AUDIT_FSGID: |
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case AUDIT_OBJ_GID: |
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case AUDIT_PID: |
|
case AUDIT_MSGTYPE: |
|
case AUDIT_PPID: |
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case AUDIT_DEVMAJOR: |
|
case AUDIT_EXIT: |
|
case AUDIT_SUCCESS: |
|
case AUDIT_INODE: |
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case AUDIT_SESSIONID: |
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case AUDIT_SUBJ_SEN: |
|
case AUDIT_SUBJ_CLR: |
|
case AUDIT_OBJ_LEV_LOW: |
|
case AUDIT_OBJ_LEV_HIGH: |
|
case AUDIT_SADDR_FAM: |
|
/* bit ops are only useful on syscall args */ |
|
if (f->op == Audit_bitmask || f->op == Audit_bittest) |
|
return -EINVAL; |
|
break; |
|
case AUDIT_SUBJ_USER: |
|
case AUDIT_SUBJ_ROLE: |
|
case AUDIT_SUBJ_TYPE: |
|
case AUDIT_OBJ_USER: |
|
case AUDIT_OBJ_ROLE: |
|
case AUDIT_OBJ_TYPE: |
|
case AUDIT_WATCH: |
|
case AUDIT_DIR: |
|
case AUDIT_FILTERKEY: |
|
case AUDIT_LOGINUID_SET: |
|
case AUDIT_ARCH: |
|
case AUDIT_FSTYPE: |
|
case AUDIT_PERM: |
|
case AUDIT_FILETYPE: |
|
case AUDIT_FIELD_COMPARE: |
|
case AUDIT_EXE: |
|
/* only equal and not equal valid ops */ |
|
if (f->op != Audit_not_equal && f->op != Audit_equal) |
|
return -EINVAL; |
|
break; |
|
default: |
|
/* field not recognized */ |
|
return -EINVAL; |
|
} |
|
|
|
/* Check for select valid field values */ |
|
switch (f->type) { |
|
case AUDIT_LOGINUID_SET: |
|
if ((f->val != 0) && (f->val != 1)) |
|
return -EINVAL; |
|
break; |
|
case AUDIT_PERM: |
|
if (f->val & ~15) |
|
return -EINVAL; |
|
break; |
|
case AUDIT_FILETYPE: |
|
if (f->val & ~S_IFMT) |
|
return -EINVAL; |
|
break; |
|
case AUDIT_FIELD_COMPARE: |
|
if (f->val > AUDIT_MAX_FIELD_COMPARE) |
|
return -EINVAL; |
|
break; |
|
case AUDIT_SADDR_FAM: |
|
if (f->val >= AF_MAX) |
|
return -EINVAL; |
|
break; |
|
default: |
|
break; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/* Translate struct audit_rule_data to kernel's rule representation. */ |
|
static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, |
|
size_t datasz) |
|
{ |
|
int err = 0; |
|
struct audit_entry *entry; |
|
void *bufp; |
|
size_t remain = datasz - sizeof(struct audit_rule_data); |
|
int i; |
|
char *str; |
|
struct audit_fsnotify_mark *audit_mark; |
|
|
|
entry = audit_to_entry_common(data); |
|
if (IS_ERR(entry)) |
|
goto exit_nofree; |
|
|
|
bufp = data->buf; |
|
for (i = 0; i < data->field_count; i++) { |
|
struct audit_field *f = &entry->rule.fields[i]; |
|
u32 f_val; |
|
|
|
err = -EINVAL; |
|
|
|
f->op = audit_to_op(data->fieldflags[i]); |
|
if (f->op == Audit_bad) |
|
goto exit_free; |
|
|
|
f->type = data->fields[i]; |
|
f_val = data->values[i]; |
|
|
|
/* Support legacy tests for a valid loginuid */ |
|
if ((f->type == AUDIT_LOGINUID) && (f_val == AUDIT_UID_UNSET)) { |
|
f->type = AUDIT_LOGINUID_SET; |
|
f_val = 0; |
|
entry->rule.pflags |= AUDIT_LOGINUID_LEGACY; |
|
} |
|
|
|
err = audit_field_valid(entry, f); |
|
if (err) |
|
goto exit_free; |
|
|
|
err = -EINVAL; |
|
switch (f->type) { |
|
case AUDIT_LOGINUID: |
|
case AUDIT_UID: |
|
case AUDIT_EUID: |
|
case AUDIT_SUID: |
|
case AUDIT_FSUID: |
|
case AUDIT_OBJ_UID: |
|
f->uid = make_kuid(current_user_ns(), f_val); |
|
if (!uid_valid(f->uid)) |
|
goto exit_free; |
|
break; |
|
case AUDIT_GID: |
|
case AUDIT_EGID: |
|
case AUDIT_SGID: |
|
case AUDIT_FSGID: |
|
case AUDIT_OBJ_GID: |
|
f->gid = make_kgid(current_user_ns(), f_val); |
|
if (!gid_valid(f->gid)) |
|
goto exit_free; |
|
break; |
|
case AUDIT_ARCH: |
|
f->val = f_val; |
|
entry->rule.arch_f = f; |
|
break; |
|
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: |
|
str = audit_unpack_string(&bufp, &remain, f_val); |
|
if (IS_ERR(str)) { |
|
err = PTR_ERR(str); |
|
goto exit_free; |
|
} |
|
entry->rule.buflen += f_val; |
|
f->lsm_str = str; |
|
err = security_audit_rule_init(f->type, f->op, str, |
|
(void **)&f->lsm_rule); |
|
/* Keep currently invalid fields around in case they |
|
* become valid after a policy reload. */ |
|
if (err == -EINVAL) { |
|
pr_warn("audit rule for LSM \'%s\' is invalid\n", |
|
str); |
|
err = 0; |
|
} else if (err) |
|
goto exit_free; |
|
break; |
|
case AUDIT_WATCH: |
|
str = audit_unpack_string(&bufp, &remain, f_val); |
|
if (IS_ERR(str)) { |
|
err = PTR_ERR(str); |
|
goto exit_free; |
|
} |
|
err = audit_to_watch(&entry->rule, str, f_val, f->op); |
|
if (err) { |
|
kfree(str); |
|
goto exit_free; |
|
} |
|
entry->rule.buflen += f_val; |
|
break; |
|
case AUDIT_DIR: |
|
str = audit_unpack_string(&bufp, &remain, f_val); |
|
if (IS_ERR(str)) { |
|
err = PTR_ERR(str); |
|
goto exit_free; |
|
} |
|
err = audit_make_tree(&entry->rule, str, f->op); |
|
kfree(str); |
|
if (err) |
|
goto exit_free; |
|
entry->rule.buflen += f_val; |
|
break; |
|
case AUDIT_INODE: |
|
f->val = f_val; |
|
err = audit_to_inode(&entry->rule, f); |
|
if (err) |
|
goto exit_free; |
|
break; |
|
case AUDIT_FILTERKEY: |
|
if (entry->rule.filterkey || f_val > AUDIT_MAX_KEY_LEN) |
|
goto exit_free; |
|
str = audit_unpack_string(&bufp, &remain, f_val); |
|
if (IS_ERR(str)) { |
|
err = PTR_ERR(str); |
|
goto exit_free; |
|
} |
|
entry->rule.buflen += f_val; |
|
entry->rule.filterkey = str; |
|
break; |
|
case AUDIT_EXE: |
|
if (entry->rule.exe || f_val > PATH_MAX) |
|
goto exit_free; |
|
str = audit_unpack_string(&bufp, &remain, f_val); |
|
if (IS_ERR(str)) { |
|
err = PTR_ERR(str); |
|
goto exit_free; |
|
} |
|
audit_mark = audit_alloc_mark(&entry->rule, str, f_val); |
|
if (IS_ERR(audit_mark)) { |
|
kfree(str); |
|
err = PTR_ERR(audit_mark); |
|
goto exit_free; |
|
} |
|
entry->rule.buflen += f_val; |
|
entry->rule.exe = audit_mark; |
|
break; |
|
default: |
|
f->val = f_val; |
|
break; |
|
} |
|
} |
|
|
|
if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal) |
|
entry->rule.inode_f = NULL; |
|
|
|
exit_nofree: |
|
return entry; |
|
|
|
exit_free: |
|
if (entry->rule.tree) |
|
audit_put_tree(entry->rule.tree); /* that's the temporary one */ |
|
if (entry->rule.exe) |
|
audit_remove_mark(entry->rule.exe); /* that's the template one */ |
|
audit_free_rule(entry); |
|
return ERR_PTR(err); |
|
} |
|
|
|
/* Pack a filter field's string representation into data block. */ |
|
static inline size_t audit_pack_string(void **bufp, const char *str) |
|
{ |
|
size_t len = strlen(str); |
|
|
|
memcpy(*bufp, str, len); |
|
*bufp += len; |
|
|
|
return len; |
|
} |
|
|
|
/* Translate kernel rule representation to struct audit_rule_data. */ |
|
static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule) |
|
{ |
|
struct audit_rule_data *data; |
|
void *bufp; |
|
int i; |
|
|
|
data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL); |
|
if (unlikely(!data)) |
|
return NULL; |
|
memset(data, 0, sizeof(*data)); |
|
|
|
data->flags = krule->flags | krule->listnr; |
|
data->action = krule->action; |
|
data->field_count = krule->field_count; |
|
bufp = data->buf; |
|
for (i = 0; i < data->field_count; i++) { |
|
struct audit_field *f = &krule->fields[i]; |
|
|
|
data->fields[i] = f->type; |
|
data->fieldflags[i] = audit_ops[f->op]; |
|
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: |
|
data->buflen += data->values[i] = |
|
audit_pack_string(&bufp, f->lsm_str); |
|
break; |
|
case AUDIT_WATCH: |
|
data->buflen += data->values[i] = |
|
audit_pack_string(&bufp, |
|
audit_watch_path(krule->watch)); |
|
break; |
|
case AUDIT_DIR: |
|
data->buflen += data->values[i] = |
|
audit_pack_string(&bufp, |
|
audit_tree_path(krule->tree)); |
|
break; |
|
case AUDIT_FILTERKEY: |
|
data->buflen += data->values[i] = |
|
audit_pack_string(&bufp, krule->filterkey); |
|
break; |
|
case AUDIT_EXE: |
|
data->buflen += data->values[i] = |
|
audit_pack_string(&bufp, audit_mark_path(krule->exe)); |
|
break; |
|
case AUDIT_LOGINUID_SET: |
|
if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) { |
|
data->fields[i] = AUDIT_LOGINUID; |
|
data->values[i] = AUDIT_UID_UNSET; |
|
break; |
|
} |
|
fallthrough; /* if set */ |
|
default: |
|
data->values[i] = f->val; |
|
} |
|
} |
|
for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i]; |
|
|
|
return data; |
|
} |
|
|
|
/* Compare two rules in kernel format. Considered success if rules |
|
* don't match. */ |
|
static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b) |
|
{ |
|
int i; |
|
|
|
if (a->flags != b->flags || |
|
a->pflags != b->pflags || |
|
a->listnr != b->listnr || |
|
a->action != b->action || |
|
a->field_count != b->field_count) |
|
return 1; |
|
|
|
for (i = 0; i < a->field_count; i++) { |
|
if (a->fields[i].type != b->fields[i].type || |
|
a->fields[i].op != b->fields[i].op) |
|
return 1; |
|
|
|
switch(a->fields[i].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: |
|
if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str)) |
|
return 1; |
|
break; |
|
case AUDIT_WATCH: |
|
if (strcmp(audit_watch_path(a->watch), |
|
audit_watch_path(b->watch))) |
|
return 1; |
|
break; |
|
case AUDIT_DIR: |
|
if (strcmp(audit_tree_path(a->tree), |
|
audit_tree_path(b->tree))) |
|
return 1; |
|
break; |
|
case AUDIT_FILTERKEY: |
|
/* both filterkeys exist based on above type compare */ |
|
if (strcmp(a->filterkey, b->filterkey)) |
|
return 1; |
|
break; |
|
case AUDIT_EXE: |
|
/* both paths exist based on above type compare */ |
|
if (strcmp(audit_mark_path(a->exe), |
|
audit_mark_path(b->exe))) |
|
return 1; |
|
break; |
|
case AUDIT_UID: |
|
case AUDIT_EUID: |
|
case AUDIT_SUID: |
|
case AUDIT_FSUID: |
|
case AUDIT_LOGINUID: |
|
case AUDIT_OBJ_UID: |
|
if (!uid_eq(a->fields[i].uid, b->fields[i].uid)) |
|
return 1; |
|
break; |
|
case AUDIT_GID: |
|
case AUDIT_EGID: |
|
case AUDIT_SGID: |
|
case AUDIT_FSGID: |
|
case AUDIT_OBJ_GID: |
|
if (!gid_eq(a->fields[i].gid, b->fields[i].gid)) |
|
return 1; |
|
break; |
|
default: |
|
if (a->fields[i].val != b->fields[i].val) |
|
return 1; |
|
} |
|
} |
|
|
|
for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
|
if (a->mask[i] != b->mask[i]) |
|
return 1; |
|
|
|
return 0; |
|
} |
|
|
|
/* Duplicate LSM field information. The lsm_rule is opaque, so must be |
|
* re-initialized. */ |
|
static inline int audit_dupe_lsm_field(struct audit_field *df, |
|
struct audit_field *sf) |
|
{ |
|
int ret = 0; |
|
char *lsm_str; |
|
|
|
/* our own copy of lsm_str */ |
|
lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL); |
|
if (unlikely(!lsm_str)) |
|
return -ENOMEM; |
|
df->lsm_str = lsm_str; |
|
|
|
/* our own (refreshed) copy of lsm_rule */ |
|
ret = security_audit_rule_init(df->type, df->op, df->lsm_str, |
|
(void **)&df->lsm_rule); |
|
/* Keep currently invalid fields around in case they |
|
* become valid after a policy reload. */ |
|
if (ret == -EINVAL) { |
|
pr_warn("audit rule for LSM \'%s\' is invalid\n", |
|
df->lsm_str); |
|
ret = 0; |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
/* Duplicate an audit rule. This will be a deep copy with the exception |
|
* of the watch - that pointer is carried over. The LSM specific fields |
|
* will be updated in the copy. The point is to be able to replace the old |
|
* rule with the new rule in the filterlist, then free the old rule. |
|
* The rlist element is undefined; list manipulations are handled apart from |
|
* the initial copy. */ |
|
struct audit_entry *audit_dupe_rule(struct audit_krule *old) |
|
{ |
|
u32 fcount = old->field_count; |
|
struct audit_entry *entry; |
|
struct audit_krule *new; |
|
char *fk; |
|
int i, err = 0; |
|
|
|
entry = audit_init_entry(fcount); |
|
if (unlikely(!entry)) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
new = &entry->rule; |
|
new->flags = old->flags; |
|
new->pflags = old->pflags; |
|
new->listnr = old->listnr; |
|
new->action = old->action; |
|
for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
|
new->mask[i] = old->mask[i]; |
|
new->prio = old->prio; |
|
new->buflen = old->buflen; |
|
new->inode_f = old->inode_f; |
|
new->field_count = old->field_count; |
|
|
|
/* |
|
* note that we are OK with not refcounting here; audit_match_tree() |
|
* never dereferences tree and we can't get false positives there |
|
* since we'd have to have rule gone from the list *and* removed |
|
* before the chunks found by lookup had been allocated, i.e. before |
|
* the beginning of list scan. |
|
*/ |
|
new->tree = old->tree; |
|
memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount); |
|
|
|
/* deep copy this information, updating the lsm_rule fields, because |
|
* the originals will all be freed when the old rule is freed. */ |
|
for (i = 0; i < fcount; i++) { |
|
switch (new->fields[i].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: |
|
err = audit_dupe_lsm_field(&new->fields[i], |
|
&old->fields[i]); |
|
break; |
|
case AUDIT_FILTERKEY: |
|
fk = kstrdup(old->filterkey, GFP_KERNEL); |
|
if (unlikely(!fk)) |
|
err = -ENOMEM; |
|
else |
|
new->filterkey = fk; |
|
break; |
|
case AUDIT_EXE: |
|
err = audit_dupe_exe(new, old); |
|
break; |
|
} |
|
if (err) { |
|
if (new->exe) |
|
audit_remove_mark(new->exe); |
|
audit_free_rule(entry); |
|
return ERR_PTR(err); |
|
} |
|
} |
|
|
|
if (old->watch) { |
|
audit_get_watch(old->watch); |
|
new->watch = old->watch; |
|
} |
|
|
|
return entry; |
|
} |
|
|
|
/* Find an existing audit rule. |
|
* Caller must hold audit_filter_mutex to prevent stale rule data. */ |
|
static struct audit_entry *audit_find_rule(struct audit_entry *entry, |
|
struct list_head **p) |
|
{ |
|
struct audit_entry *e, *found = NULL; |
|
struct list_head *list; |
|
int h; |
|
|
|
if (entry->rule.inode_f) { |
|
h = audit_hash_ino(entry->rule.inode_f->val); |
|
*p = list = &audit_inode_hash[h]; |
|
} else if (entry->rule.watch) { |
|
/* we don't know the inode number, so must walk entire hash */ |
|
for (h = 0; h < AUDIT_INODE_BUCKETS; h++) { |
|
list = &audit_inode_hash[h]; |
|
list_for_each_entry(e, list, list) |
|
if (!audit_compare_rule(&entry->rule, &e->rule)) { |
|
found = e; |
|
goto out; |
|
} |
|
} |
|
goto out; |
|
} else { |
|
*p = list = &audit_filter_list[entry->rule.listnr]; |
|
} |
|
|
|
list_for_each_entry(e, list, list) |
|
if (!audit_compare_rule(&entry->rule, &e->rule)) { |
|
found = e; |
|
goto out; |
|
} |
|
|
|
out: |
|
return found; |
|
} |
|
|
|
static u64 prio_low = ~0ULL/2; |
|
static u64 prio_high = ~0ULL/2 - 1; |
|
|
|
/* Add rule to given filterlist if not a duplicate. */ |
|
static inline int audit_add_rule(struct audit_entry *entry) |
|
{ |
|
struct audit_entry *e; |
|
struct audit_watch *watch = entry->rule.watch; |
|
struct audit_tree *tree = entry->rule.tree; |
|
struct list_head *list; |
|
int err = 0; |
|
#ifdef CONFIG_AUDITSYSCALL |
|
int dont_count = 0; |
|
|
|
/* If any of these, don't count towards total */ |
|
switch(entry->rule.listnr) { |
|
case AUDIT_FILTER_USER: |
|
case AUDIT_FILTER_EXCLUDE: |
|
case AUDIT_FILTER_FS: |
|
dont_count = 1; |
|
} |
|
#endif |
|
|
|
mutex_lock(&audit_filter_mutex); |
|
e = audit_find_rule(entry, &list); |
|
if (e) { |
|
mutex_unlock(&audit_filter_mutex); |
|
err = -EEXIST; |
|
/* normally audit_add_tree_rule() will free it on failure */ |
|
if (tree) |
|
audit_put_tree(tree); |
|
return err; |
|
} |
|
|
|
if (watch) { |
|
/* audit_filter_mutex is dropped and re-taken during this call */ |
|
err = audit_add_watch(&entry->rule, &list); |
|
if (err) { |
|
mutex_unlock(&audit_filter_mutex); |
|
/* |
|
* normally audit_add_tree_rule() will free it |
|
* on failure |
|
*/ |
|
if (tree) |
|
audit_put_tree(tree); |
|
return err; |
|
} |
|
} |
|
if (tree) { |
|
err = audit_add_tree_rule(&entry->rule); |
|
if (err) { |
|
mutex_unlock(&audit_filter_mutex); |
|
return err; |
|
} |
|
} |
|
|
|
entry->rule.prio = ~0ULL; |
|
if (entry->rule.listnr == AUDIT_FILTER_EXIT) { |
|
if (entry->rule.flags & AUDIT_FILTER_PREPEND) |
|
entry->rule.prio = ++prio_high; |
|
else |
|
entry->rule.prio = --prio_low; |
|
} |
|
|
|
if (entry->rule.flags & AUDIT_FILTER_PREPEND) { |
|
list_add(&entry->rule.list, |
|
&audit_rules_list[entry->rule.listnr]); |
|
list_add_rcu(&entry->list, list); |
|
entry->rule.flags &= ~AUDIT_FILTER_PREPEND; |
|
} else { |
|
list_add_tail(&entry->rule.list, |
|
&audit_rules_list[entry->rule.listnr]); |
|
list_add_tail_rcu(&entry->list, list); |
|
} |
|
#ifdef CONFIG_AUDITSYSCALL |
|
if (!dont_count) |
|
audit_n_rules++; |
|
|
|
if (!audit_match_signal(entry)) |
|
audit_signals++; |
|
#endif |
|
mutex_unlock(&audit_filter_mutex); |
|
|
|
return err; |
|
} |
|
|
|
/* Remove an existing rule from filterlist. */ |
|
int audit_del_rule(struct audit_entry *entry) |
|
{ |
|
struct audit_entry *e; |
|
struct audit_tree *tree = entry->rule.tree; |
|
struct list_head *list; |
|
int ret = 0; |
|
#ifdef CONFIG_AUDITSYSCALL |
|
int dont_count = 0; |
|
|
|
/* If any of these, don't count towards total */ |
|
switch(entry->rule.listnr) { |
|
case AUDIT_FILTER_USER: |
|
case AUDIT_FILTER_EXCLUDE: |
|
case AUDIT_FILTER_FS: |
|
dont_count = 1; |
|
} |
|
#endif |
|
|
|
mutex_lock(&audit_filter_mutex); |
|
e = audit_find_rule(entry, &list); |
|
if (!e) { |
|
ret = -ENOENT; |
|
goto out; |
|
} |
|
|
|
if (e->rule.watch) |
|
audit_remove_watch_rule(&e->rule); |
|
|
|
if (e->rule.tree) |
|
audit_remove_tree_rule(&e->rule); |
|
|
|
if (e->rule.exe) |
|
audit_remove_mark_rule(&e->rule); |
|
|
|
#ifdef CONFIG_AUDITSYSCALL |
|
if (!dont_count) |
|
audit_n_rules--; |
|
|
|
if (!audit_match_signal(entry)) |
|
audit_signals--; |
|
#endif |
|
|
|
list_del_rcu(&e->list); |
|
list_del(&e->rule.list); |
|
call_rcu(&e->rcu, audit_free_rule_rcu); |
|
|
|
out: |
|
mutex_unlock(&audit_filter_mutex); |
|
|
|
if (tree) |
|
audit_put_tree(tree); /* that's the temporary one */ |
|
|
|
return ret; |
|
} |
|
|
|
/* List rules using struct audit_rule_data. */ |
|
static void audit_list_rules(int seq, struct sk_buff_head *q) |
|
{ |
|
struct sk_buff *skb; |
|
struct audit_krule *r; |
|
int i; |
|
|
|
/* This is a blocking read, so use audit_filter_mutex instead of rcu |
|
* iterator to sync with list writers. */ |
|
for (i=0; i<AUDIT_NR_FILTERS; i++) { |
|
list_for_each_entry(r, &audit_rules_list[i], list) { |
|
struct audit_rule_data *data; |
|
|
|
data = audit_krule_to_data(r); |
|
if (unlikely(!data)) |
|
break; |
|
skb = audit_make_reply(seq, AUDIT_LIST_RULES, 0, 1, |
|
data, |
|
sizeof(*data) + data->buflen); |
|
if (skb) |
|
skb_queue_tail(q, skb); |
|
kfree(data); |
|
} |
|
} |
|
skb = audit_make_reply(seq, AUDIT_LIST_RULES, 1, 1, NULL, 0); |
|
if (skb) |
|
skb_queue_tail(q, skb); |
|
} |
|
|
|
/* Log rule additions and removals */ |
|
static void audit_log_rule_change(char *action, struct audit_krule *rule, int res) |
|
{ |
|
struct audit_buffer *ab; |
|
|
|
if (!audit_enabled) |
|
return; |
|
|
|
ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
|
if (!ab) |
|
return; |
|
audit_log_session_info(ab); |
|
audit_log_task_context(ab); |
|
audit_log_format(ab, " op=%s", action); |
|
audit_log_key(ab, rule->filterkey); |
|
audit_log_format(ab, " list=%d res=%d", rule->listnr, res); |
|
audit_log_end(ab); |
|
} |
|
|
|
/** |
|
* audit_rule_change - apply all rules to the specified message type |
|
* @type: audit message type |
|
* @seq: netlink audit message sequence (serial) number |
|
* @data: payload data |
|
* @datasz: size of payload data |
|
*/ |
|
int audit_rule_change(int type, int seq, void *data, size_t datasz) |
|
{ |
|
int err = 0; |
|
struct audit_entry *entry; |
|
|
|
switch (type) { |
|
case AUDIT_ADD_RULE: |
|
entry = audit_data_to_entry(data, datasz); |
|
if (IS_ERR(entry)) |
|
return PTR_ERR(entry); |
|
err = audit_add_rule(entry); |
|
audit_log_rule_change("add_rule", &entry->rule, !err); |
|
break; |
|
case AUDIT_DEL_RULE: |
|
entry = audit_data_to_entry(data, datasz); |
|
if (IS_ERR(entry)) |
|
return PTR_ERR(entry); |
|
err = audit_del_rule(entry); |
|
audit_log_rule_change("remove_rule", &entry->rule, !err); |
|
break; |
|
default: |
|
WARN_ON(1); |
|
return -EINVAL; |
|
} |
|
|
|
if (err || type == AUDIT_DEL_RULE) { |
|
if (entry->rule.exe) |
|
audit_remove_mark(entry->rule.exe); |
|
audit_free_rule(entry); |
|
} |
|
|
|
return err; |
|
} |
|
|
|
/** |
|
* audit_list_rules_send - list the audit rules |
|
* @request_skb: skb of request we are replying to (used to target the reply) |
|
* @seq: netlink audit message sequence (serial) number |
|
*/ |
|
int audit_list_rules_send(struct sk_buff *request_skb, int seq) |
|
{ |
|
struct task_struct *tsk; |
|
struct audit_netlink_list *dest; |
|
|
|
/* We can't just spew out the rules here because we might fill |
|
* the available socket buffer space and deadlock waiting for |
|
* auditctl to read from it... which isn't ever going to |
|
* happen if we're actually running in the context of auditctl |
|
* trying to _send_ the stuff */ |
|
|
|
dest = kmalloc(sizeof(*dest), GFP_KERNEL); |
|
if (!dest) |
|
return -ENOMEM; |
|
dest->net = get_net(sock_net(NETLINK_CB(request_skb).sk)); |
|
dest->portid = NETLINK_CB(request_skb).portid; |
|
skb_queue_head_init(&dest->q); |
|
|
|
mutex_lock(&audit_filter_mutex); |
|
audit_list_rules(seq, &dest->q); |
|
mutex_unlock(&audit_filter_mutex); |
|
|
|
tsk = kthread_run(audit_send_list_thread, dest, "audit_send_list"); |
|
if (IS_ERR(tsk)) { |
|
skb_queue_purge(&dest->q); |
|
put_net(dest->net); |
|
kfree(dest); |
|
return PTR_ERR(tsk); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
int audit_comparator(u32 left, u32 op, u32 right) |
|
{ |
|
switch (op) { |
|
case Audit_equal: |
|
return (left == right); |
|
case Audit_not_equal: |
|
return (left != right); |
|
case Audit_lt: |
|
return (left < right); |
|
case Audit_le: |
|
return (left <= right); |
|
case Audit_gt: |
|
return (left > right); |
|
case Audit_ge: |
|
return (left >= right); |
|
case Audit_bitmask: |
|
return (left & right); |
|
case Audit_bittest: |
|
return ((left & right) == right); |
|
default: |
|
return 0; |
|
} |
|
} |
|
|
|
int audit_uid_comparator(kuid_t left, u32 op, kuid_t right) |
|
{ |
|
switch (op) { |
|
case Audit_equal: |
|
return uid_eq(left, right); |
|
case Audit_not_equal: |
|
return !uid_eq(left, right); |
|
case Audit_lt: |
|
return uid_lt(left, right); |
|
case Audit_le: |
|
return uid_lte(left, right); |
|
case Audit_gt: |
|
return uid_gt(left, right); |
|
case Audit_ge: |
|
return uid_gte(left, right); |
|
case Audit_bitmask: |
|
case Audit_bittest: |
|
default: |
|
return 0; |
|
} |
|
} |
|
|
|
int audit_gid_comparator(kgid_t left, u32 op, kgid_t right) |
|
{ |
|
switch (op) { |
|
case Audit_equal: |
|
return gid_eq(left, right); |
|
case Audit_not_equal: |
|
return !gid_eq(left, right); |
|
case Audit_lt: |
|
return gid_lt(left, right); |
|
case Audit_le: |
|
return gid_lte(left, right); |
|
case Audit_gt: |
|
return gid_gt(left, right); |
|
case Audit_ge: |
|
return gid_gte(left, right); |
|
case Audit_bitmask: |
|
case Audit_bittest: |
|
default: |
|
return 0; |
|
} |
|
} |
|
|
|
/** |
|
* parent_len - find the length of the parent portion of a pathname |
|
* @path: pathname of which to determine length |
|
*/ |
|
int parent_len(const char *path) |
|
{ |
|
int plen; |
|
const char *p; |
|
|
|
plen = strlen(path); |
|
|
|
if (plen == 0) |
|
return plen; |
|
|
|
/* disregard trailing slashes */ |
|
p = path + plen - 1; |
|
while ((*p == '/') && (p > path)) |
|
p--; |
|
|
|
/* walk backward until we find the next slash or hit beginning */ |
|
while ((*p != '/') && (p > path)) |
|
p--; |
|
|
|
/* did we find a slash? Then increment to include it in path */ |
|
if (*p == '/') |
|
p++; |
|
|
|
return p - path; |
|
} |
|
|
|
/** |
|
* audit_compare_dname_path - compare given dentry name with last component in |
|
* given path. Return of 0 indicates a match. |
|
* @dname: dentry name that we're comparing |
|
* @path: full pathname that we're comparing |
|
* @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL |
|
* here indicates that we must compute this value. |
|
*/ |
|
int audit_compare_dname_path(const struct qstr *dname, const char *path, int parentlen) |
|
{ |
|
int dlen, pathlen; |
|
const char *p; |
|
|
|
dlen = dname->len; |
|
pathlen = strlen(path); |
|
if (pathlen < dlen) |
|
return 1; |
|
|
|
parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen; |
|
if (pathlen - parentlen != dlen) |
|
return 1; |
|
|
|
p = path + parentlen; |
|
|
|
return strncmp(p, dname->name, dlen); |
|
} |
|
|
|
int audit_filter(int msgtype, unsigned int listtype) |
|
{ |
|
struct audit_entry *e; |
|
int ret = 1; /* Audit by default */ |
|
|
|
rcu_read_lock(); |
|
list_for_each_entry_rcu(e, &audit_filter_list[listtype], list) { |
|
int i, result = 0; |
|
|
|
for (i = 0; i < e->rule.field_count; i++) { |
|
struct audit_field *f = &e->rule.fields[i]; |
|
pid_t pid; |
|
u32 sid; |
|
|
|
switch (f->type) { |
|
case AUDIT_PID: |
|
pid = task_pid_nr(current); |
|
result = audit_comparator(pid, f->op, f->val); |
|
break; |
|
case AUDIT_UID: |
|
result = audit_uid_comparator(current_uid(), f->op, f->uid); |
|
break; |
|
case AUDIT_GID: |
|
result = audit_gid_comparator(current_gid(), f->op, f->gid); |
|
break; |
|
case AUDIT_LOGINUID: |
|
result = audit_uid_comparator(audit_get_loginuid(current), |
|
f->op, f->uid); |
|
break; |
|
case AUDIT_LOGINUID_SET: |
|
result = audit_comparator(audit_loginuid_set(current), |
|
f->op, f->val); |
|
break; |
|
case AUDIT_MSGTYPE: |
|
result = audit_comparator(msgtype, f->op, f->val); |
|
break; |
|
case AUDIT_SUBJ_USER: |
|
case AUDIT_SUBJ_ROLE: |
|
case AUDIT_SUBJ_TYPE: |
|
case AUDIT_SUBJ_SEN: |
|
case AUDIT_SUBJ_CLR: |
|
if (f->lsm_rule) { |
|
security_task_getsecid_subj(current, |
|
&sid); |
|
result = security_audit_rule_match(sid, |
|
f->type, f->op, f->lsm_rule); |
|
} |
|
break; |
|
case AUDIT_EXE: |
|
result = audit_exe_compare(current, e->rule.exe); |
|
if (f->op == Audit_not_equal) |
|
result = !result; |
|
break; |
|
default: |
|
goto unlock_and_return; |
|
} |
|
if (result < 0) /* error */ |
|
goto unlock_and_return; |
|
if (!result) |
|
break; |
|
} |
|
if (result > 0) { |
|
if (e->rule.action == AUDIT_NEVER || listtype == AUDIT_FILTER_EXCLUDE) |
|
ret = 0; |
|
break; |
|
} |
|
} |
|
unlock_and_return: |
|
rcu_read_unlock(); |
|
return ret; |
|
} |
|
|
|
static int update_lsm_rule(struct audit_krule *r) |
|
{ |
|
struct audit_entry *entry = container_of(r, struct audit_entry, rule); |
|
struct audit_entry *nentry; |
|
int err = 0; |
|
|
|
if (!security_audit_rule_known(r)) |
|
return 0; |
|
|
|
nentry = audit_dupe_rule(r); |
|
if (entry->rule.exe) |
|
audit_remove_mark(entry->rule.exe); |
|
if (IS_ERR(nentry)) { |
|
/* save the first error encountered for the |
|
* return value */ |
|
err = PTR_ERR(nentry); |
|
audit_panic("error updating LSM filters"); |
|
if (r->watch) |
|
list_del(&r->rlist); |
|
list_del_rcu(&entry->list); |
|
list_del(&r->list); |
|
} else { |
|
if (r->watch || r->tree) |
|
list_replace_init(&r->rlist, &nentry->rule.rlist); |
|
list_replace_rcu(&entry->list, &nentry->list); |
|
list_replace(&r->list, &nentry->rule.list); |
|
} |
|
call_rcu(&entry->rcu, audit_free_rule_rcu); |
|
|
|
return err; |
|
} |
|
|
|
/* This function will re-initialize the lsm_rule field of all applicable rules. |
|
* It will traverse the filter lists serarching for rules that contain LSM |
|
* specific filter fields. When such a rule is found, it is copied, the |
|
* LSM field is re-initialized, and the old rule is replaced with the |
|
* updated rule. */ |
|
int audit_update_lsm_rules(void) |
|
{ |
|
struct audit_krule *r, *n; |
|
int i, err = 0; |
|
|
|
/* audit_filter_mutex synchronizes the writers */ |
|
mutex_lock(&audit_filter_mutex); |
|
|
|
for (i = 0; i < AUDIT_NR_FILTERS; i++) { |
|
list_for_each_entry_safe(r, n, &audit_rules_list[i], list) { |
|
int res = update_lsm_rule(r); |
|
if (!err) |
|
err = res; |
|
} |
|
} |
|
mutex_unlock(&audit_filter_mutex); |
|
|
|
return err; |
|
}
|
|
|