Re: [PATCH] cifs: cope with negative dentries in cifs_get_root

On Tue, Aug 09, 2011 at 09:41:33AM +0400, Pavel Shilovsky wrote:

quoted

? ? ? ? ? ? ? ?mutex_unlock(&dir->i_mutex);
? ? ? ? ? ? ? ?dput(dentry);
? ? ? ? ? ? ? ?dentry = child;
+ ? ? ? ? ? ? ? if (!dentry->d_inode) {

dentry can be NULL here (returned from lookup_one_len) and it can
cause a null pointer dereference.

Not NULL, ERR_PTR(...).  IOW, we need to check IS_ERR(dentry) to protect
that check of dentry->d_inode.