From: Sasha Levin <sasha.levin@oracle.com>
Date: Thu, 4 Oct 2012 23:57:31 +0000 (-0400)
Subject: fs: handle failed audit_log_start properly
X-Git-Tag: v3.7-rc1~42^2~15
X-Git-Url: http://pileus.org/git/?a=commitdiff_plain;h=d1c7d97ad58836affde6e39980b96527510b572e;hp=ffd8d101a3a7d3f2e79deee1e342801703b6dc70;p=~andy%2Flinux

fs: handle failed audit_log_start properly

audit_log_start() may return NULL, this is unchecked by the caller in
audit_log_link_denied() and could cause a NULL ptr deref.

Introduced by commit a51d9eaa ("fs: add link restriction audit reporting").

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---

diff --git a/kernel/audit.c b/kernel/audit.c
index 4d0ceede331..40414e9143d 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1440,6 +1440,8 @@ void audit_log_link_denied(const char *operation, struct path *link)
 
 	ab = audit_log_start(current->audit_context, GFP_KERNEL,
 			     AUDIT_ANOM_LINK);
+	if (!ab)
+		return;
 	audit_log_format(ab, "op=%s action=denied", operation);
 	audit_log_format(ab, " pid=%d comm=", current->pid);
 	audit_log_untrustedstring(ab, current->comm);