From ba7261af2b030ab2c06189be1fc77b273716839f Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 8 Apr 2022 11:08:58 -0600 Subject: io_uring: fix race between timeout flush and removal commit e677edbcabee849bfdd43f1602bccbecf736a646 upstream. io_flush_timeouts() assumes the timeout isn't in progress of triggering or being removed/canceled, so it unconditionally removes it from the timeout list and attempts to cancel it. Leave it on the list and let the normal timeout cancelation take care of it. Cc: stable@vger.kernel.org # 5.5+ Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- fs/io_uring.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/fs/io_uring.c b/fs/io_uring.c index a3a175965929..3d44d48b35ea 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1538,12 +1538,11 @@ static 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); + struct io_kiocb *req, *tmp; spin_lock_irq(&ctx->timeout_lock); - while (!list_empty(&ctx->timeout_list)) { + list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) { u32 events_needed, events_got; - struct io_kiocb *req = list_first_entry(&ctx->timeout_list, - struct io_kiocb, timeout.list); if (io_is_timeout_noseq(req)) break; @@ -1560,7 +1559,6 @@ static void io_flush_timeouts(struct io_ring_ctx *ctx) if (events_got < events_needed) break; - list_del_init(&req->timeout.list); io_kill_timeout(req, 0); } ctx->cq_last_tm_flush = seq; @@ -6205,6 +6203,7 @@ static int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe, if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr))) return -EFAULT; + INIT_LIST_HEAD(&req->timeout.list); data->mode = io_translate_timeout_mode(flags); hrtimer_init(&data->timer, io_timeout_get_clock(data), data->mode); -- cgit v1.2.3