From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0DEC3C46467 for ; Sat, 14 Jan 2023 09:52:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229733AbjANJwD (ORCPT ); Sat, 14 Jan 2023 04:52:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230149AbjANJwD (ORCPT ); Sat, 14 Jan 2023 04:52:03 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6CC66A2 for ; Sat, 14 Jan 2023 01:52:02 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 10A31B808C5 for ; Sat, 14 Jan 2023 09:52:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 24519C433D2; Sat, 14 Jan 2023 09:51:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673689919; bh=dgSY/ukZIPG3UynjeogY56fnlOwycgeb44ImjWPARwg=; h=Subject:To:Cc:From:Date:From; b=HlWB9PJBbBthiST1OGkHAUFLCQ7pH7O63RlgkXCkznhy419vL68sKUwYOHQzc0x3Z OfeLE8Wf1fenUBMg/9oZLry+4vVPT4i8GwPLT85ItxJxwnb05vxqPu5FZm5dOh1uiJ pbZzstV/Y2hHhut8hl0OhGCzPKQJoKzcTFGLLjEc= Subject: FAILED: patch "[PATCH] io_uring: lock overflowing for IOPOLL" failed to apply to 6.1-stable tree To: asml.silence@gmail.com, axboe@kernel.dk Cc: From: Date: Sat, 14 Jan 2023 10:51:51 +0100 Message-ID: <1673689911293@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . Possible dependencies: 544d163d659d ("io_uring: lock overflowing for IOPOLL") a8cf95f93610 ("io_uring: fix overflow handling regression") fa18fa2272c7 ("io_uring: inline __io_req_complete_put()") f9d567c75ec2 ("io_uring: inline __io_req_complete_post()") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 544d163d659d45a206d8929370d5a2984e546cb7 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Thu, 12 Jan 2023 13:08:56 +0000 Subject: [PATCH] io_uring: lock overflowing for IOPOLL MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit syzbot reports an issue with overflow filling for IOPOLL: WARNING: CPU: 0 PID: 28 at io_uring/io_uring.c:734 io_cqring_event_overflow+0x1c0/0x230 io_uring/io_uring.c:734 CPU: 0 PID: 28 Comm: kworker/u4:1 Not tainted 6.2.0-rc3-syzkaller-16369-g358a161a6a9e #0 Workqueue: events_unbound io_ring_exit_work Call trace:  io_cqring_event_overflow+0x1c0/0x230 io_uring/io_uring.c:734  io_req_cqe_overflow+0x5c/0x70 io_uring/io_uring.c:773  io_fill_cqe_req io_uring/io_uring.h:168 [inline]  io_do_iopoll+0x474/0x62c io_uring/rw.c:1065  io_iopoll_try_reap_events+0x6c/0x108 io_uring/io_uring.c:1513  io_uring_try_cancel_requests+0x13c/0x258 io_uring/io_uring.c:3056  io_ring_exit_work+0xec/0x390 io_uring/io_uring.c:2869  process_one_work+0x2d8/0x504 kernel/workqueue.c:2289  worker_thread+0x340/0x610 kernel/workqueue.c:2436  kthread+0x12c/0x158 kernel/kthread.c:376  ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:863 There is no real problem for normal IOPOLL as flush is also called with uring_lock taken, but it's getting more complicated for IOPOLL|SQPOLL, for which __io_cqring_overflow_flush() happens from the CQ waiting path. Reported-and-tested-by: syzbot+6805087452d72929404e@syzkaller.appspotmail.com Cc: stable@vger.kernel.org # 5.10+ Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe diff --git a/io_uring/rw.c b/io_uring/rw.c index 8227af2e1c0f..9c3ddd46a1ad 100644 --- a/io_uring/rw.c +++ b/io_uring/rw.c @@ -1062,7 +1062,11 @@ int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin) continue; req->cqe.flags = io_put_kbuf(req, 0); - io_fill_cqe_req(req->ctx, req); + if (unlikely(!__io_fill_cqe_req(ctx, req))) { + spin_lock(&ctx->completion_lock); + io_req_cqe_overflow(req); + spin_unlock(&ctx->completion_lock); + } } if (unlikely(!nr_events))