From d9516f346e8b8e9c7dd37976a06a5bde1a871d6f Mon Sep 17 00:00:00 2001
From: Gaosheng Cui <cuigaosheng1@huawei.com>
Date: Sat, 16 Oct 2021 15:23:51 +0800
Subject: [PATCH] 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>
---
kernel/auditsc.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index a4ba53f5354ea..6efb0bb909d09 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -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);
--
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