From: Jens Axboe axboe@kernel.dk
commit febb985c06cb6f5fac63598c0bffd4fd823d110d upstream.
If we don't, then we may lose access to it completely, leading to a request leak. This will eventually stall the ring exit process as well.
Cc: stable@vger.kernel.org Fixes: 49f1c68e048f ("io_uring: optimise submission side poll_refs") Reported-and-tested-by: syzbot+6c95df01470a47fc3af4@syzkaller.appspotmail.com Link: https://lore.kernel.org/io-uring/0000000000009f829805f1ce87b2@google.com/ Suggested-by: Pavel Begunkov asml.silence@gmail.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- io_uring/poll.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-)
--- a/io_uring/poll.c +++ b/io_uring/poll.c @@ -549,6 +549,14 @@ static bool io_poll_can_finish_inline(st return pt->owning || io_poll_get_ownership(req); }
+static void io_poll_add_hash(struct io_kiocb *req) +{ + if (req->flags & REQ_F_HASH_LOCKED) + io_poll_req_insert_locked(req); + else + io_poll_req_insert(req); +} + /* * Returns 0 when it's handed over for polling. The caller owns the requests if * it returns non-zero, but otherwise should not touch it. Negative values @@ -607,18 +615,17 @@ static int __io_arm_poll_handler(struct
if (mask && ((poll->events & (EPOLLET|EPOLLONESHOT)) == (EPOLLET|EPOLLONESHOT))) { - if (!io_poll_can_finish_inline(req, ipt)) + if (!io_poll_can_finish_inline(req, ipt)) { + io_poll_add_hash(req); return 0; + } io_poll_remove_entries(req); ipt->result_mask = mask; /* no one else has access to the req, forget about the ref */ return 1; }
- if (req->flags & REQ_F_HASH_LOCKED) - io_poll_req_insert_locked(req); - else - io_poll_req_insert(req); + io_poll_add_hash(req);
if (mask && (poll->events & EPOLLET) && io_poll_can_finish_inline(req, ipt)) {