Re: [PATCH -next, v2 1/2] audit: fix possible null-pointer dereference in audit_filter_rules
On Wed, Oct 13, 2021 at 5:10 AM Gaosheng Cui <cuigaosheng1(a)huawei.com> wrote:
Fix this possible null-pointer dereference in audit_filter_rules.
Thanks for fixing this, just a couple of small comments:
I think you can drop the description text below here, the code snippet
is just a duplicate of the code and the error message is pretty
obvious.
If ctx is null, a null-pointer dereference will occur:
case AUDIT_SADDR_FAM:
if (ctx->sockaddr)
...
break;
audit_filter_rules() error: we previously assumed 'ctx' could be null
Reported-by: kernel test robot <lkp(a)intel.com>
Reported-by: Dan Carpenter <dan.carpenter(a)oracle.com>
Signed-off-by: Gaosheng Cui <cuigaosheng1(a)huawei.com>
I would also add a Fixes tag, for example:
Fixes: bf361231c295 ("audit: add saddr_fam filter field")
---
kernel/auditsc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 4ba3b8573ff4..42d4a4320526 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -647,7 +647,7 @@ static int audit_filter_rules(struct task_struct *tsk,
result = audit_comparator(audit_loginuid_set(tsk), f->op,
f->val);
break;
case AUDIT_SADDR_FAM:
- if (ctx->sockaddr)
+ if (ctx && ctx->sockaddr)
result =
audit_comparator(ctx->sockaddr->ss_family,
f->op, f->val);
break;
--
2.30.0
--
paul moore
www.paul-moore.com