Commit f5bc1e75 authored by Pavel Shilovsky's avatar Pavel Shilovsky Committed by Steve French

CIFS: Fix oops while mounting with prefixpath

commit fec11dd9 caused
a regression when we have already mounted //server/share/a
and want to mount //server/share/a/b.

The problem is that lookup_one_len calls __lookup_hash
with nd pointer as NULL. Then __lookup_hash calls
do_revalidate in the case when dentry exists and we end
up with NULL pointer deference in cifs_d_revalidate:

if (nd->flags & LOOKUP_RCU)
	return -ECHILD;

Fix this by checking nd for NULL.
Signed-off-by: default avatarPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: default avatarShirish Pargaonkar <shirishp@us.ibm.com>
CC: Stable <stable@kernel.org>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent e010a5ef
......@@ -636,7 +636,7 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
static int
cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
{
if (nd->flags & LOOKUP_RCU)
if (nd && (nd->flags & LOOKUP_RCU))
return -ECHILD;
if (direntry->d_inode) {
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment