mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-06 02:24:14 +08:00
4ebd7651bf
Of the three LSMs that implement the security_task_getsecid() LSM hook, all three LSMs provide the task's objective security credentials. This turns out to be unfortunate as most of the hook's callers seem to expect the task's subjective credentials, although a small handful of callers do correctly expect the objective credentials. This patch is the first step towards fixing the problem: it splits the existing security_task_getsecid() hook into two variants, one for the subjective creds, one for the objective creds. void security_task_getsecid_subj(struct task_struct *p, u32 *secid); void security_task_getsecid_obj(struct task_struct *p, u32 *secid); While this patch does fix all of the callers to use the correct variant, in order to keep this patch focused on the callers and to ease review, the LSMs continue to use the same implementation for both hooks. The net effect is that this patch should not change the behavior of the kernel in any way, it will be up to the latter LSM specific patches in this series to change the hook implementations and return the correct credentials. Acked-by: Mimi Zohar <zohar@linux.ibm.com> (IMA) Acked-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
1448 lines
34 KiB
C
1448 lines
34 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/* auditfilter.c -- filtering of audit events
|
|
*
|
|
* Copyright 2003-2004 Red Hat, Inc.
|
|
* Copyright 2005 Hewlett-Packard Development Company, L.P.
|
|
* Copyright 2005 IBM Corporation
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/audit.h>
|
|
#include <linux/kthread.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/namei.h>
|
|
#include <linux/netlink.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/security.h>
|
|
#include <net/net_namespace.h>
|
|
#include <net/sock.h>
|
|
#include "audit.h"
|
|
|
|
/*
|
|
* Locking model:
|
|
*
|
|
* audit_filter_mutex:
|
|
* Synchronizes writes and blocking reads of audit's filterlist
|
|
* data. Rcu is used to traverse the filterlist and access
|
|
* contents of structs audit_entry, audit_watch and opaque
|
|
* LSM rules during filtering. If modified, these structures
|
|
* must be copied and replace their counterparts in the filterlist.
|
|
* An audit_parent struct is not accessed during filtering, so may
|
|
* be written directly provided audit_filter_mutex is held.
|
|
*/
|
|
|
|
/* Audit filter lists, defined in <linux/audit.h> */
|
|
struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
|
|
LIST_HEAD_INIT(audit_filter_list[0]),
|
|
LIST_HEAD_INIT(audit_filter_list[1]),
|
|
LIST_HEAD_INIT(audit_filter_list[2]),
|
|
LIST_HEAD_INIT(audit_filter_list[3]),
|
|
LIST_HEAD_INIT(audit_filter_list[4]),
|
|
LIST_HEAD_INIT(audit_filter_list[5]),
|
|
LIST_HEAD_INIT(audit_filter_list[6]),
|
|
#if AUDIT_NR_FILTERS != 7
|
|
#error Fix audit_filter_list initialiser
|
|
#endif
|
|
};
|
|
static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = {
|
|
LIST_HEAD_INIT(audit_rules_list[0]),
|
|
LIST_HEAD_INIT(audit_rules_list[1]),
|
|
LIST_HEAD_INIT(audit_rules_list[2]),
|
|
LIST_HEAD_INIT(audit_rules_list[3]),
|
|
LIST_HEAD_INIT(audit_rules_list[4]),
|
|
LIST_HEAD_INIT(audit_rules_list[5]),
|
|
LIST_HEAD_INIT(audit_rules_list[6]),
|
|
};
|
|
|
|
DEFINE_MUTEX(audit_filter_mutex);
|
|
|
|
static void audit_free_lsm_field(struct audit_field *f)
|
|
{
|
|
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:
|
|
kfree(f->lsm_str);
|
|
security_audit_rule_free(f->lsm_rule);
|
|
}
|
|
}
|
|
|
|
static inline void audit_free_rule(struct audit_entry *e)
|
|
{
|
|
int i;
|
|
struct audit_krule *erule = &e->rule;
|
|
|
|
/* some rules don't have associated watches */
|
|
if (erule->watch)
|
|
audit_put_watch(erule->watch);
|
|
if (erule->fields)
|
|
for (i = 0; i < erule->field_count; i++)
|
|
audit_free_lsm_field(&erule->fields[i]);
|
|
kfree(erule->fields);
|
|
kfree(erule->filterkey);
|
|
kfree(e);
|
|
}
|
|
|
|
void audit_free_rule_rcu(struct rcu_head *head)
|
|
{
|
|
struct audit_entry *e = container_of(head, struct audit_entry, rcu);
|
|
audit_free_rule(e);
|
|
}
|
|
|
|
/* Initialize an audit filterlist entry. */
|
|
static inline struct audit_entry *audit_init_entry(u32 field_count)
|
|
{
|
|
struct audit_entry *entry;
|
|
struct audit_field *fields;
|
|
|
|
entry = kzalloc(sizeof(*entry), GFP_KERNEL);
|
|
if (unlikely(!entry))
|
|
return NULL;
|
|
|
|
fields = kcalloc(field_count, sizeof(*fields), GFP_KERNEL);
|
|
if (unlikely(!fields)) {
|
|
kfree(entry);
|
|
return NULL;
|
|
}
|
|
entry->rule.fields = fields;
|
|
|
|
return entry;
|
|
}
|
|
|
|
/* Unpack a filter field's string representation from user-space
|
|
* buffer. */
|
|
char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
|
|
{
|
|
char *str;
|
|
|
|
if (!*bufp || (len == 0) || (len > *remain))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
/* Of the currently implemented string fields, PATH_MAX
|
|
* defines the longest valid length.
|
|
*/
|
|
if (len > PATH_MAX)
|
|
return ERR_PTR(-ENAMETOOLONG);
|
|
|
|
str = kmalloc(len + 1, GFP_KERNEL);
|
|
if (unlikely(!str))
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
memcpy(str, *bufp, len);
|
|
str[len] = 0;
|
|
*bufp += len;
|
|
*remain -= len;
|
|
|
|
return str;
|
|
}
|
|
|
|
/* Translate an inode field to kernel representation. */
|
|
static inline int audit_to_inode(struct audit_krule *krule,
|
|
struct audit_field *f)
|
|
{
|
|
if (krule->listnr != AUDIT_FILTER_EXIT ||
|
|
krule->inode_f || krule->watch || krule->tree ||
|
|
(f->op != Audit_equal && f->op != Audit_not_equal))
|
|
return -EINVAL;
|
|
|
|
krule->inode_f = f;
|
|
return 0;
|
|
}
|
|
|
|
static __u32 *classes[AUDIT_SYSCALL_CLASSES];
|
|
|
|
int __init audit_register_class(int class, unsigned *list)
|
|
{
|
|
__u32 *p = kcalloc(AUDIT_BITMASK_SIZE, sizeof(__u32), GFP_KERNEL);
|
|
if (!p)
|
|
return -ENOMEM;
|
|
while (*list != ~0U) {
|
|
unsigned n = *list++;
|
|
if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
|
|
kfree(p);
|
|
return -EINVAL;
|
|
}
|
|
p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
|
|
}
|
|
if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
|
|
kfree(p);
|
|
return -EINVAL;
|
|
}
|
|
classes[class] = p;
|
|
return 0;
|
|
}
|
|
|
|
int audit_match_class(int class, unsigned syscall)
|
|
{
|
|
if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
|
|
return 0;
|
|
if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
|
|
return 0;
|
|
return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
|
|
}
|
|
|
|
#ifdef CONFIG_AUDITSYSCALL
|
|
static inline int audit_match_class_bits(int class, u32 *mask)
|
|
{
|
|
int i;
|
|
|
|
if (classes[class]) {
|
|
for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
|
|
if (mask[i] & classes[class][i])
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static int audit_match_signal(struct audit_entry *entry)
|
|
{
|
|
struct audit_field *arch = entry->rule.arch_f;
|
|
|
|
if (!arch) {
|
|
/* When arch is unspecified, we must check both masks on biarch
|
|
* as syscall number alone is ambiguous. */
|
|
return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
|
|
entry->rule.mask) &&
|
|
audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
|
|
entry->rule.mask));
|
|
}
|
|
|
|
switch(audit_classify_arch(arch->val)) {
|
|
case 0: /* native */
|
|
return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
|
|
entry->rule.mask));
|
|
case 1: /* 32bit on biarch */
|
|
return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
|
|
entry->rule.mask));
|
|
default:
|
|
return 1;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* Common user-space to kernel rule translation. */
|
|
static inline struct audit_entry *audit_to_entry_common(struct audit_rule_data *rule)
|
|
{
|
|
unsigned listnr;
|
|
struct audit_entry *entry;
|
|
int i, err;
|
|
|
|
err = -EINVAL;
|
|
listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
|
|
switch(listnr) {
|
|
default:
|
|
goto exit_err;
|
|
#ifdef CONFIG_AUDITSYSCALL
|
|
case AUDIT_FILTER_ENTRY:
|
|
pr_err("AUDIT_FILTER_ENTRY is deprecated\n");
|
|
goto exit_err;
|
|
case AUDIT_FILTER_EXIT:
|
|
case AUDIT_FILTER_TASK:
|
|
#endif
|
|
case AUDIT_FILTER_USER:
|
|
case AUDIT_FILTER_EXCLUDE:
|
|
case AUDIT_FILTER_FS:
|
|
;
|
|
}
|
|
if (unlikely(rule->action == AUDIT_POSSIBLE)) {
|
|
pr_err("AUDIT_POSSIBLE is deprecated\n");
|
|
goto exit_err;
|
|
}
|
|
if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
|
|
goto exit_err;
|
|
if (rule->field_count > AUDIT_MAX_FIELDS)
|
|
goto exit_err;
|
|
|
|
err = -ENOMEM;
|
|
entry = audit_init_entry(rule->field_count);
|
|
if (!entry)
|
|
goto exit_err;
|
|
|
|
entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
|
|
entry->rule.listnr = listnr;
|
|
entry->rule.action = rule->action;
|
|
entry->rule.field_count = rule->field_count;
|
|
|
|
for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
|
|
entry->rule.mask[i] = rule->mask[i];
|
|
|
|
for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
|
|
int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
|
|
__u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
|
|
__u32 *class;
|
|
|
|
if (!(*p & AUDIT_BIT(bit)))
|
|
continue;
|
|
*p &= ~AUDIT_BIT(bit);
|
|
class = classes[i];
|
|
if (class) {
|
|
int j;
|
|
for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
|
|
entry->rule.mask[j] |= class[j];
|
|
}
|
|
}
|
|
|
|
return entry;
|
|
|
|
exit_err:
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
static u32 audit_ops[] =
|
|
{
|
|
[Audit_equal] = AUDIT_EQUAL,
|
|
[Audit_not_equal] = AUDIT_NOT_EQUAL,
|
|
[Audit_bitmask] = AUDIT_BIT_MASK,
|
|
[Audit_bittest] = AUDIT_BIT_TEST,
|
|
[Audit_lt] = AUDIT_LESS_THAN,
|
|
[Audit_gt] = AUDIT_GREATER_THAN,
|
|
[Audit_le] = AUDIT_LESS_THAN_OR_EQUAL,
|
|
[Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL,
|
|
};
|
|
|
|
static u32 audit_to_op(u32 op)
|
|
{
|
|
u32 n;
|
|
for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++)
|
|
;
|
|
return n;
|
|
}
|
|
|
|
/* check if an audit field is valid */
|
|
static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
|
|
{
|
|
switch (f->type) {
|
|
case AUDIT_MSGTYPE:
|
|
if (entry->rule.listnr != AUDIT_FILTER_EXCLUDE &&
|
|
entry->rule.listnr != AUDIT_FILTER_USER)
|
|
return -EINVAL;
|
|
break;
|
|
case AUDIT_FSTYPE:
|
|
if (entry->rule.listnr != AUDIT_FILTER_FS)
|
|
return -EINVAL;
|
|
break;
|
|
}
|
|
|
|
switch (entry->rule.listnr) {
|
|
case AUDIT_FILTER_FS:
|
|
switch(f->type) {
|
|
case AUDIT_FSTYPE:
|
|
case AUDIT_FILTERKEY:
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/* Check for valid field type and op */
|
|
switch (f->type) {
|
|
case AUDIT_ARG0:
|
|
case AUDIT_ARG1:
|
|
case AUDIT_ARG2:
|
|
case AUDIT_ARG3:
|
|
case AUDIT_PERS: /* <uapi/linux/personality.h> */
|
|
case AUDIT_DEVMINOR:
|
|
/* all ops are valid */
|
|
break;
|
|
case AUDIT_UID:
|
|
case AUDIT_EUID:
|
|
case AUDIT_SUID:
|
|
case AUDIT_FSUID:
|
|
case AUDIT_LOGINUID:
|
|
case AUDIT_OBJ_UID:
|
|
case AUDIT_GID:
|
|
case AUDIT_EGID:
|
|
case AUDIT_SGID:
|
|
case AUDIT_FSGID:
|
|
case AUDIT_OBJ_GID:
|
|
case AUDIT_PID:
|
|
case AUDIT_MSGTYPE:
|
|
case AUDIT_PPID:
|
|
case AUDIT_DEVMAJOR:
|
|
case AUDIT_EXIT:
|
|
case AUDIT_SUCCESS:
|
|
case AUDIT_INODE:
|
|
case AUDIT_SESSIONID:
|
|
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;
|
|
}
|