may_follow_link() should use nd->inode

Now that we can get there in RCU mode, we shouldn't play with
nd->path.dentry->d_inode - it's not guaranteed to be stable.
Use nd->inode instead.

Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/namei.c b/fs/namei.c
index fbbcf09..1c2105e 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -879,7 +879,7 @@ static inline int may_follow_link(struct nameidata *nd)
                return 0;
 
        /* Allowed if parent directory not sticky and world-writable. */
-       parent = nd->path.dentry->d_inode;
+       parent = nd->inode;
        if ((parent->i_mode & (S_ISVTX|S_IWOTH)) != (S_ISVTX|S_IWOTH))
                return 0;