io_uring: fix uninit old data for poll event upd
Both IORING_POLL_UPDATE_EVENTS and IORING_POLL_UPDATE_USER_DATA need
old_user_data to find/cancel a poll request, but it's set only for the
first one.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/ab08fd35b7652e977f9a475f01741b04102297f1.1618278933.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 1af8bb5..57ee3d2 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -5379,17 +5379,17 @@ static int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe
if (!(flags & IORING_POLL_ADD_MULTI))
events |= EPOLLONESHOT;
poll->update_events = poll->update_user_data = false;
- if (flags & IORING_POLL_UPDATE_EVENTS) {
- poll->update_events = true;
+
+ if (flags & (IORING_POLL_UPDATE_EVENTS|IORING_POLL_UPDATE_USER_DATA)) {
poll->old_user_data = READ_ONCE(sqe->addr);
+ poll->update_events = flags & IORING_POLL_UPDATE_EVENTS;
+ poll->update_user_data = flags & IORING_POLL_UPDATE_USER_DATA;
+ if (poll->update_user_data)
+ poll->new_user_data = READ_ONCE(sqe->off);
+ } else {
+ if (sqe->off || sqe->addr)
+ return -EINVAL;
}
- if (flags & IORING_POLL_UPDATE_USER_DATA) {
- poll->update_user_data = true;
- poll->new_user_data = READ_ONCE(sqe->off);
- }
- if (!(poll->update_events || poll->update_user_data) &&
- (sqe->off || sqe->addr))
- return -EINVAL;
poll->events = demangle_poll(events) |
(events & (EPOLLEXCLUSIVE|EPOLLONESHOT));
return 0;