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;
