audit: return early if the filter rule has a lower priority

It is not necessary for audit_filter_rules() functions to check
audit fileds of the rule with a lower priority, and if we did,
there might be some unintended effects, such as the ctx->ppid
may be changed unexpectedly, so return early if the rule has
a lower priority.

Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
[PM: slight tweak to the subject line]
Signed-off-by: Paul Moore <paul@paul-moore.com>
This commit is contained in:
Gaosheng Cui 2021-10-16 15:23:51 +08:00 committed by Paul Moore
parent 571e5c0efc
commit d9516f346e

View File

@ -470,6 +470,9 @@ static int audit_filter_rules(struct task_struct *tsk,
u32 sid;
unsigned int sessionid;
if (ctx && rule->prio <= ctx->prio)
return 0;
cred = rcu_dereference_check(tsk->cred, tsk == current || task_creation);
for (i = 0; i < rule->field_count; i++) {
@ -737,8 +740,6 @@ static int audit_filter_rules(struct task_struct *tsk,
}
if (ctx) {
if (rule->prio <= ctx->prio)
return 0;
if (rule->filterkey) {
kfree(ctx->filterkey);
ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC);