From 94c0d4ecbe7f9fe56e052b26b2ab484e246c07b4 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 12 Jul 2011 21:40:23 -0400 Subject: [PATCH] Fix ->d_lock locking order in unlazy_walk() Make sure that child is still a child of parent before nested locking of child->d_lock in unlazy_walk(); otherwise we are risking a violation of locking order and deadlocks. Signed-off-by: Al Viro --- fs/namei.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/namei.c b/fs/namei.c index 0223c41fb114..5c867dd1c0b3 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -433,6 +433,8 @@ static int unlazy_walk(struct nameidata *nd, struct dentry *dentry) goto err_parent; BUG_ON(nd->inode != parent->d_inode); } else { + if (dentry->d_parent != parent) + goto err_parent; spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED); if (!__d_rcu_to_refcount(dentry, nd->seq)) goto err_child; -- 2.30.2