aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorAndy Lutomirski <luto@amacapital.net>2014-05-28 23:09:58 -0400
committerWilly Tarreau <w@1wt.eu>2014-06-19 00:26:00 +0200
commita986d9c350c41fbb56b75d9da04a9725a044454a (patch)
tree2eccda36accc2f995b6eb0afcd758e59185b4282
parent07bc7fb4fcff0e24cc25abea01742e1f07d37246 (diff)
downloadlinux-linaro-stable-a986d9c350c41fbb56b75d9da04a9725a044454a.tar.gz
auditsc: audit_krule mask accesses need bounds checking
Fixes an easy DoS and possible information disclosure. This does nothing about the broken state of x32 auditing. eparis: If the admin has enabled auditd and has specifically loaded audit rules. This bug has been around since before git. Wow... Cc: stable@vger.kernel.org Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> (cherry picked from commit a3c54931199565930d6d84f4c3456f6440aefd41) [wt: no audit_filter_inode_name(), applied to audit_filter_inodes() instead] Signed-off-by: Willy Tarreau <w@1wt.eu>
-rw-r--r--kernel/auditsc.c25
1 files changed, 18 insertions, 7 deletions
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 267e484f0198..b6998efa7ebe 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -680,6 +680,22 @@ static enum audit_state audit_filter_task(struct task_struct *tsk, char **key)
return AUDIT_BUILD_CONTEXT;
}
+static int audit_in_mask(const struct audit_krule *rule, unsigned long val)
+{
+ int word, bit;
+
+ if (val > 0xffffffff)
+ return false;
+
+ word = AUDIT_WORD(val);
+ if (word >= AUDIT_BITMASK_SIZE)
+ return false;
+
+ bit = AUDIT_BIT(val);
+
+ return rule->mask[word] & bit;
+}
+
/* At syscall entry and exit time, this filter is called if the
* audit_state is not low enough that auditing cannot take place, but is
* also not high enough that we already know we have to write an audit
@@ -697,11 +713,8 @@ static enum audit_state audit_filter_syscall(struct task_struct *tsk,
rcu_read_lock();
if (!list_empty(list)) {
- int word = AUDIT_WORD(ctx->major);
- int bit = AUDIT_BIT(ctx->major);
-
list_for_each_entry_rcu(e, list, list) {
- if ((e->rule.mask[word] & bit) == bit &&
+ if (audit_in_mask(&e->rule, ctx->major) &&
audit_filter_rules(tsk, &e->rule, ctx, NULL,
&state)) {
rcu_read_unlock();
@@ -730,8 +743,6 @@ void audit_filter_inodes(struct task_struct *tsk, struct audit_context *ctx)
rcu_read_lock();
for (i = 0; i < ctx->name_count; i++) {
- int word = AUDIT_WORD(ctx->major);
- int bit = AUDIT_BIT(ctx->major);
struct audit_names *n = &ctx->names[i];
int h = audit_hash_ino((u32)n->ino);
struct list_head *list = &audit_inode_hash[h];
@@ -740,7 +751,7 @@ void audit_filter_inodes(struct task_struct *tsk, struct audit_context *ctx)
continue;
list_for_each_entry_rcu(e, list, list) {
- if ((e->rule.mask[word] & bit) == bit &&
+ if (audit_in_mask(&e->rule, ctx->major) &&
audit_filter_rules(tsk, &e->rule, ctx, n, &state)) {
rcu_read_unlock();
ctx->current_state = state;