This is a note to let you know that I've just added the patch titled io_uring: protect cq_timeouts with timeout_lock to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: io_uring-protect-cq_timeouts-with-timeout_lock.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From ea011ee10231f5fa6cbb415007048ca0bb948baf Mon Sep 17 00:00:00 2001 From: Pavel Begunkov <asml.silence@xxxxxxxxx> Date: Fri, 2 Dec 2022 17:47:22 +0000 Subject: io_uring: protect cq_timeouts with timeout_lock From: Pavel Begunkov <asml.silence@xxxxxxxxx> commit ea011ee10231f5fa6cbb415007048ca0bb948baf upstream. Read cq_timeouts in io_flush_timeouts() only after taking the timeout_lock, as it's protected by it. There are many places where we also grab ->completion_lock, but for instance io_timeout_fn() doesn't and still modifies cq_timeouts. Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx> Link: https://lore.kernel.org/r/9c79544dd6cf5c4018cb1bab99cf481a93ea46ef.1670002973.git.asml.silence@xxxxxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- io_uring/timeout.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/io_uring/timeout.c +++ b/io_uring/timeout.c @@ -72,10 +72,12 @@ static bool io_kill_timeout(struct io_ki __cold void io_flush_timeouts(struct io_ring_ctx *ctx) __must_hold(&ctx->completion_lock) { - u32 seq = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts); + u32 seq; struct io_timeout *timeout, *tmp; spin_lock_irq(&ctx->timeout_lock); + seq = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts); + list_for_each_entry_safe(timeout, tmp, &ctx->timeout_list, list) { struct io_kiocb *req = cmd_to_io_kiocb(timeout); u32 events_needed, events_got; Patches currently in stable-queue which might be from asml.silence@xxxxxxxxx are queue-6.1/io_uring-net-introduce-ioring_send_zc_report_usage-flag.patch queue-6.1/io_uring-net-fix-cleanup-after-recycle.patch queue-6.1/io_uring-dont-remove-file-from-msg_ring-reqs.patch queue-6.1/io_uring-protect-cq_timeouts-with-timeout_lock.patch queue-6.1/io_uring-add-completion-locking-for-iopoll.patch queue-6.1/io_uring-improve-io_double_lock_ctx-fail-handling.patch