From a890d01e4ee016978776e45340e521b3bbbdf41f Mon Sep 17 00:00:00 2001 From: Hao Xu Date: Wed, 28 Jul 2021 11:03:22 +0800 Subject: io_uring: fix poll requests leaking second poll entries For pure poll requests, it doesn't remove the second poll wait entry when it's done, neither after vfs_poll() or in the poll completion handler. We should remove the second poll wait entry. And we use io_poll_remove_double() rather than io_poll_remove_waitqs() since the latter has some redundant logic. Fixes: 88e41cf928a6 ("io_uring: add multishot mode for IORING_OP_POLL_ADD") Cc: stable@vger.kernel.org # 5.13+ Signed-off-by: Hao Xu Link: https://lore.kernel.org/r/20210728030322.12307-1-haoxu@linux.alibaba.com Signed-off-by: Jens Axboe --- fs/io_uring.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 83f67d33bf67..bf548af0426c 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -4939,7 +4939,6 @@ static bool io_poll_complete(struct io_kiocb *req, __poll_t mask) if (req->poll.events & EPOLLONESHOT) flags = 0; if (!io_cqring_fill_event(ctx, req->user_data, error, flags)) { - io_poll_remove_waitqs(req); req->poll.done = true; flags = 0; } @@ -4962,6 +4961,7 @@ static void io_poll_task_func(struct io_kiocb *req) done = io_poll_complete(req, req->result); if (done) { + io_poll_remove_double(req); hash_del(&req->hash_node); } else { req->result = 0; @@ -5149,7 +5149,7 @@ static __poll_t __io_arm_poll_handler(struct io_kiocb *req, ipt->error = -EINVAL; spin_lock_irq(&ctx->completion_lock); - if (ipt->error) + if (ipt->error || (mask && (poll->events & EPOLLONESHOT))) io_poll_remove_double(req); if (likely(poll->head)) { spin_lock(&poll->head->lock); @@ -5221,7 +5221,6 @@ static int io_arm_poll_handler(struct io_kiocb *req) ret = __io_arm_poll_handler(req, &apoll->poll, &ipt, mask, io_async_wake); if (ret || ipt.error) { - io_poll_remove_double(req); spin_unlock_irq(&ctx->completion_lock); if (ret) return IO_APOLL_READY; -- cgit v1.2.3