| Message ID | 14abef4b-c217-4ec1-93d6-9c0950e972b9@kernel.dk (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | io_uring/poll: fix upper bits poll updating | expand |
On 3/13/24 3:26 PM, Jens Axboe wrote: > If IORING_POLL_UPDATE_EVENTS is used to updated the mask of a pending > poll request, then we mask off the bottom 16 bits and mask in the new > ones. But this prevents updating higher entry bits, which wasn't the > intent. > > Rather than play masking games, simply overwrite the existing poll > entry mask with the new one. This can't work, some of the upper flags will decide state. So just disregard this one!
diff --git a/io_uring/poll.c b/io_uring/poll.c index 5f779139cae1..721f42a14c3e 100644 --- a/io_uring/poll.c +++ b/io_uring/poll.c @@ -1030,8 +1030,7 @@ int io_poll_remove(struct io_kiocb *req, unsigned int issue_flags) if (poll_update->update_events) { struct io_poll *poll = io_kiocb_to_cmd(preq, struct io_poll); - poll->events &= ~0xffff; - poll->events |= poll_update->events & 0xffff; + poll->events = poll_update->events; poll->events |= IO_POLL_UNMASK; } if (poll_update->update_user_data)
If IORING_POLL_UPDATE_EVENTS is used to updated the mask of a pending poll request, then we mask off the bottom 16 bits and mask in the new ones. But this prevents updating higher entry bits, which wasn't the intent. Rather than play masking games, simply overwrite the existing poll entry mask with the new one. Cc: stable@vger.kernel.org Fixes: b69de288e913 ("io_uring: allow events and user_data update of running poll requests") Link: https://github.com/axboe/liburing/issues/1099 Signed-off-by: Jens Axboe <axboe@kernel.dk> ---