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 aa30d19e9edd75acf05780cad24eadbf37fba910..6d47fac64292e0155ef925ef78be737f4bf826ab 100644 (file)
--- 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;
 }