From bf77ae4c98d721a9aae3840970d46669a78e034a Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 3 Jan 2019 11:04:08 +1100 Subject: [PATCH] locks: fix error in locks_move_blocks() After moving all requests from fl->fl_blocked_requests to new->fl_blocked_requests it is nonsensical to do anything to all the remaining elements, there aren't any. This should do something to all the requests that have been moved. For simplicity, it does it to all requests in the target list. Setting "f->fl_blocker = new" to all members of new->fl_blocked_requests is "obviously correct" as it preserves the invariant of the linkage among requests. Reported-by: syzbot+239d99847eb49ecb3899@syzkaller.appspotmail.com Fixes: 5946c4319ebb ("fs/locks: allow a lock request to block other requests.") Signed-off-by: NeilBrown Signed-off-by: Jeff Layton --- fs/locks.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/locks.c b/fs/locks.c index f0b24d98f36b..ff6af2c32601 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -453,7 +453,7 @@ static void locks_move_blocks(struct file_lock *new, struct file_lock *fl) return; spin_lock(&blocked_lock_lock); list_splice_init(&fl->fl_blocked_requests, &new->fl_blocked_requests); - list_for_each_entry(f, &fl->fl_blocked_requests, fl_blocked_member) + list_for_each_entry(f, &new->fl_blocked_requests, fl_blocked_member) f->fl_blocker = new; spin_unlock(&blocked_lock_lock); }