From: NeilBrown Date: Thu, 3 Jan 2019 00:04:08 +0000 (+1100) Subject: locks: fix error in locks_move_blocks() X-Git-Tag: v5.0-rc1~47^2 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=bf77ae4c98d721a9aae3840970d46669a78e034a;p=linux.git 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 --- 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); }