From: Sasha Levin <sasha.levin@oracle.com>
Date: Thu, 4 Oct 2012 23:56:40 +0000 (-0400)
Subject: fs: prevent use after free in auditing when symlink following was denied
X-Git-Tag: v3.7-rc1~42^2~16
X-Git-Url: http://pileus.org/git/?p=~andy%2Flinux;a=commitdiff_plain;h=ffd8d101a3a7d3f2e79deee1e342801703b6dc70

fs: prevent use after free in auditing when symlink following was denied

Commit "fs: add link restriction audit reporting" has added auditing of failed
attempts to follow symlinks. Unfortunately, the auditing was being done after
the struct path structure was released earlier.

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

diff --git a/fs/namei.c b/fs/namei.c
index aa30d19e9ed..6d47fac6429 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -692,9 +692,9 @@ static inline int may_follow_link(struct path *link, struct nameidata *nd)
 	if (uid_eq(parent->i_uid, inode->i_uid))
 		return 0;
 
+	audit_log_link_denied("follow_link", link);
 	path_put_conditional(link, nd);
 	path_put(&nd->path);
-	audit_log_link_denied("follow_link", link);
 	return -EACCES;
 }