From patchwork Wed Mar 10 13:23:17 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 397431 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 85A77C4332B for ; Wed, 10 Mar 2021 13:24:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5221864FF4 for ; Wed, 10 Mar 2021 13:24:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232408AbhCJNYF (ORCPT ); Wed, 10 Mar 2021 08:24:05 -0500 Received: from mail.kernel.org ([198.145.29.99]:45286 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231907AbhCJNYD (ORCPT ); Wed, 10 Mar 2021 08:24:03 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7719964FDA; Wed, 10 Mar 2021 13:24:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615382642; bh=8PnZjmJnJ8XwYFe3tQsXEMTsIshZbzpo2C7X8CHBVBY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CDo+bjXG+AXnBr496lCCyKhQyU4Ug3dgzev9LIiAOJL/nkSd+VO8JkSzQn38nHW8E IyRE0DU8JU9I2IqwqvEeGyw2GWUmLv4A4nnMvI5PQBKFZ57bQqfSbDDlPZvMuV+gzK ASgdQ68WmrQFi120HfJPiwM+BrNmJG5PDct17494= From: gregkh@linuxfoundation.org To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , syzbot+695b03d82fa8e4901b06@syzkaller.appspotmail.com, Pavel Begunkov , Jens Axboe Subject: [PATCH 5.11 04/36] io_uring: unpark SQPOLL thread for cancelation Date: Wed, 10 Mar 2021 14:23:17 +0100 Message-Id: <20210310132320.660441161@linuxfoundation.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210310132320.510840709@linuxfoundation.org> References: <20210310132320.510840709@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Greg Kroah-Hartman From: Pavel Begunkov commit 34343786ecc5ff493ca4d1f873b4386759ba52ee upstream We park SQPOLL task before going into io_uring_cancel_files(), so the task won't run task_works including those that might be important for the cancellation passes. In this case it's io_poll_remove_one(), which frees requests via io_put_req_deferred(). Unpark it for while waiting, it's ok as we disable submissions beforehand, so no new requests will be generated. INFO: task syz-executor893:8493 blocked for more than 143 seconds. Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5078 schedule+0xcf/0x270 kernel/sched/core.c:5157 io_uring_cancel_files fs/io_uring.c:8912 [inline] io_uring_cancel_task_requests+0xe70/0x11a0 fs/io_uring.c:8979 __io_uring_files_cancel+0x110/0x1b0 fs/io_uring.c:9067 io_uring_files_cancel include/linux/io_uring.h:51 [inline] do_exit+0x2fe/0x2ae0 kernel/exit.c:780 do_group_exit+0x125/0x310 kernel/exit.c:922 __do_sys_exit_group kernel/exit.c:933 [inline] __se_sys_exit_group kernel/exit.c:931 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:931 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Cc: stable@vger.kernel.org # 5.5+ Reported-by: syzbot+695b03d82fa8e4901b06@syzkaller.appspotmail.com Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- fs/io_uring.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -8955,11 +8955,16 @@ static void io_uring_cancel_files(struct break; io_uring_try_cancel_requests(ctx, task, files); + + if (ctx->sq_data) + io_sq_thread_unpark(ctx->sq_data); prepare_to_wait(&task->io_uring->wait, &wait, TASK_UNINTERRUPTIBLE); if (inflight == io_uring_count_inflight(ctx, task, files)) schedule(); finish_wait(&task->io_uring->wait, &wait); + if (ctx->sq_data) + io_sq_thread_park(ctx->sq_data); } }