From: Jens Axboe Date: Thu, 18 Sep 2025 16:21:14 +0000 (-0600) Subject: io_uring: include dying ring in task_work "should cancel" state X-Git-Tag: v6.12.49~38 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e6b2b4a0ffd856b5f0291b14ccd2f83319c15ef8;p=thirdparty%2Fkernel%2Fstable.git io_uring: include dying ring in task_work "should cancel" state Commit 3539b1467e94336d5854ebf976d9627bfb65d6c3 upstream. When running task_work for an exiting task, rather than perform the issue retry attempt, the task_work is canceled. However, this isn't done for a ring that has been closed. This can lead to requests being successfully completed post the ring being closed, which is somewhat confusing and surprising to an application. Rather than just check the task exit state, also include the ring ref state in deciding whether or not to terminate a given request when run from task_work. Cc: stable@vger.kernel.org # 6.1+ Link: https://github.com/axboe/liburing/discussions/1459 Reported-by: Benedek Thaler Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index a91dbb688b120..cbca97d9d74b1 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -1358,8 +1358,10 @@ static void io_req_task_cancel(struct io_kiocb *req, struct io_tw_state *ts) void io_req_task_submit(struct io_kiocb *req, struct io_tw_state *ts) { - io_tw_lock(req->ctx, ts); - if (unlikely(io_should_terminate_tw())) + struct io_ring_ctx *ctx = req->ctx; + + io_tw_lock(ctx, ts); + if (unlikely(io_should_terminate_tw(ctx))) io_req_defer_failed(req, -EFAULT); else if (req->flags & REQ_F_FORCE_ASYNC) io_queue_iowq(req); diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h index f2f6ba2315037..e8a3b75bc6c68 100644 --- a/io_uring/io_uring.h +++ b/io_uring/io_uring.h @@ -429,9 +429,9 @@ static inline bool io_allowed_run_tw(struct io_ring_ctx *ctx) * 2) PF_KTHREAD is set, in which case the invoker of the task_work is * our fallback task_work. */ -static inline bool io_should_terminate_tw(void) +static inline bool io_should_terminate_tw(struct io_ring_ctx *ctx) { - return current->flags & (PF_KTHREAD | PF_EXITING); + return (current->flags & (PF_KTHREAD | PF_EXITING)) || percpu_ref_is_dying(&ctx->refs); } static inline void io_req_queue_tw_complete(struct io_kiocb *req, s32 res) diff --git a/io_uring/poll.c b/io_uring/poll.c index a12ac94536062..bfdb537572f7f 100644 --- a/io_uring/poll.c +++ b/io_uring/poll.c @@ -265,7 +265,7 @@ static int io_poll_check_events(struct io_kiocb *req, struct io_tw_state *ts) { int v; - if (unlikely(io_should_terminate_tw())) + if (unlikely(io_should_terminate_tw(req->ctx))) return -ECANCELED; do { diff --git a/io_uring/timeout.c b/io_uring/timeout.c index 4ebe05085c20d..b215b2fbddd01 100644 --- a/io_uring/timeout.c +++ b/io_uring/timeout.c @@ -303,7 +303,7 @@ static void io_req_task_link_timeout(struct io_kiocb *req, struct io_tw_state *t int ret = -ENOENT; if (prev) { - if (!io_should_terminate_tw()) { + if (!io_should_terminate_tw(req->ctx)) { struct io_cancel_data cd = { .ctx = req->ctx, .data = prev->cqe.user_data, diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c index 27edb8fd639cb..f927844c8ada7 100644 --- a/io_uring/uring_cmd.c +++ b/io_uring/uring_cmd.c @@ -118,7 +118,7 @@ static void io_uring_cmd_work(struct io_kiocb *req, struct io_tw_state *ts) struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); unsigned int flags = IO_URING_F_COMPLETE_DEFER; - if (io_should_terminate_tw()) + if (io_should_terminate_tw(req->ctx)) flags |= IO_URING_F_TASK_DEAD; /* task_work executor checks the deffered list completion */