cifs: cope with negative dentries in cifs_get_root

The loop around lookup_one_len doesn't handle the case where it might
return a negative dentry, which can cause an oops on the next pass
through the loop. Check for that and break out of the loop with an
error of -ENOENT if there is one.

Fixes the panic reported here:

    https://bugzilla.redhat.com/show_bug.cgi?id=727927

Reported-by: TR Bentley <home@trarbentley.net>
Reported-by: Iain Arnell <iarnell@gmail.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: stable@kernel.org
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This commit is contained in:
Jeff Layton 2011-08-05 09:02:40 -04:00 committed by Steve French
parent f9e8c45002
commit 80975d21aa
1 changed files with 4 additions and 0 deletions

View File

@ -563,6 +563,10 @@ cifs_get_root(struct smb_vol *vol, struct super_block *sb)
mutex_unlock(&dir->i_mutex);
dput(dentry);
dentry = child;
if (!dentry->d_inode) {
dput(dentry);
dentry = ERR_PTR(-ENOENT);
}
} while (!IS_ERR(dentry));
_FreeXid(xid);
kfree(full_path);