Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs dentry reference count fix from Al Viro.

This fixes a possible inode_permission NULL pointer dereference (and
other problems) that were due to the root dentry count being decremented
too much.  In commit 48a066e72d97 ("RCU'd vfsmounts") the placement of
clearing the LOOKUP_RCU bit changed, and we then returned failure of
incrementing the lockref on the parent dentry with LOOKUP_RCU cleared.

But that meant we needed to go through the same cleanup routines that
the later failures did wrt LOOKUP_ROOT and nd->root.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fix bogus path_put() of nd->root after some unlazy_walk() failures

diff --git a/fs/namei.c b/fs/namei.c
index 8f77a8cea289350b9d0e427b284cc01a2df4691d..c53d3a9547f9295408fa3cfe0d5abfb72023e29e 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -513,8 +513,7 @@ static int unlazy_walk(struct nameidata *nd, struct dentry *dentry)
 
        if (!lockref_get_not_dead(&parent->d_lockref)) {
                nd->path.dentry = NULL; 
-               rcu_read_unlock();
-               return -ECHILD;
+               goto out;
        }
 
        /*