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 X-Spam-Level: X-Spam-Status: No, score=-6.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 9A4EEC432BE for ; Fri, 30 Jul 2021 10:39:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 842E960FE7 for ; Fri, 30 Jul 2021 10:39:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238438AbhG3KjS (ORCPT ); Fri, 30 Jul 2021 06:39:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:54408 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238629AbhG3KjO (ORCPT ); Fri, 30 Jul 2021 06:39:14 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 81E4760F6B; Fri, 30 Jul 2021 10:39:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1627641549; bh=3W1/+5Gzu0BlXunwr1Q1uIBfHX/3wsDCuqKH3tFcyEo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=NDhYyZSBEpGHYr+4NC8Gd/UW2ykj8MBGL+lxBxVK17n98MnjYrb4TOkSQka+9jXBQ zSU1L2BYxcjT71Jnpr4x3DjOKwQK+qfwfe+M1otNiZGJjL7d1hEe+QsE+91r70eDd0 WGhdxoTOFZY6KSmvKQI7BBNnS/GfcEO6Ta1iv00o= Date: Fri, 30 Jul 2021 12:39:06 +0200 From: Greg KH To: Jens Axboe Cc: Yang Yingliang , stable@vger.kernel.org Subject: Re: [PATCH 5.10] io_uring: fix null-ptr-deref in io_sq_offload_start() Message-ID: References: <20210729142338.1085951-1-yangyingliang@huawei.com> <85ef170c-8efe-e574-951b-81b3f8a62a31@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <85ef170c-8efe-e574-951b-81b3f8a62a31@kernel.dk> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Thu, Jul 29, 2021 at 02:28:28PM -0600, Jens Axboe wrote: > On 7/29/21 8:23 AM, Yang Yingliang wrote: > > I met a null-ptr-deref when doing fault-inject test: > > > > [ 65.441626][ T8299] general protection fault, probably for non-canonical address 0xdffffc0000000029: 0000 [#1] PREEMPT SMP KASAN > > [ 65.443219][ T8299] KASAN: null-ptr-deref in range [0x0000000000000148-0x000000000000014f] > > [ 65.444331][ T8299] CPU: 2 PID: 8299 Comm: test Not tainted 5.10.49+ #499 > > [ 65.445277][ T8299] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 > > [ 65.446614][ T8299] RIP: 0010:io_disable_sqo_submit+0x124/0x260 > > [ 65.447554][ T8299] Code: 7b 40 89 ee e8 2d b9 9a ff 85 ed 74 40 e8 04 b8 9a ff 49 8d be 48 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 22 01 00 00 49 8b ae 48 01 00 00 48 85 ed 74 0d > > [ 65.450860][ T8299] RSP: 0018:ffffc9000122fd70 EFLAGS: 00010202 > > [ 65.451826][ T8299] RAX: dffffc0000000000 RBX: ffff88801b11f000 RCX: ffffffff81d5d783 > > [ 65.453166][ T8299] RDX: 0000000000000029 RSI: ffffffff81d5d78c RDI: 0000000000000148 > > [ 65.454606][ T8299] RBP: 0000000000000002 R08: ffff88810168c280 R09: ffffed1003623e79 > > [ 65.456063][ T8299] R10: ffffc9000122fd70 R11: ffffed1003623e78 R12: ffff88801b11f040 > > [ 65.457542][ T8299] R13: ffff88801b11f3c0 R14: 0000000000000000 R15: 000000000000001a > > [ 65.458910][ T8299] FS: 00007ffb602e3500(0000) GS:ffff888064100000(0000) knlGS:0000000000000000 > > [ 65.460533][ T8299] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > [ 65.461736][ T8299] CR2: 00007ffb5fe7eb24 CR3: 000000010a619000 CR4: 0000000000750ee0 > > [ 65.463146][ T8299] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > [ 65.464618][ T8299] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > [ 65.466052][ T8299] PKRU: 55555554 > > [ 65.466708][ T8299] Call Trace: > > [ 65.467304][ T8299] io_uring_setup+0x2041/0x3ac0 > > [ 65.468169][ T8299] ? io_iopoll_check+0x500/0x500 > > [ 65.469123][ T8299] ? syscall_enter_from_user_mode+0x1c/0x50 > > [ 65.470241][ T8299] do_syscall_64+0x2d/0x70 > > [ 65.471028][ T8299] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > [ 65.472099][ T8299] RIP: 0033:0x7ffb5fdec839 > > [ 65.472925][ T8299] Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 1f f6 2c 00 f7 d8 64 89 01 48 > > [ 65.476465][ T8299] RSP: 002b:00007ffc33539ef8 EFLAGS: 00000206 ORIG_RAX: 00000000000001a9 > > [ 65.478026][ T8299] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ffb5fdec839 > > [ 65.479503][ T8299] RDX: 0000000020ffd000 RSI: 0000000020000080 RDI: 0000000000100001 > > [ 65.480927][ T8299] RBP: 00007ffc33539f70 R08: 0000000000000000 R09: 0000000000000000 > > [ 65.482416][ T8299] R10: 0000000000000000 R11: 0000000000000206 R12: 0000555e85531320 > > [ 65.483845][ T8299] R13: 00007ffc3353a0a0 R14: 0000000000000000 R15: 0000000000000000 > > [ 65.485331][ T8299] Modules linked in: > > [ 65.486000][ T8299] Dumping ftrace buffer: > > [ 65.486772][ T8299] (ftrace buffer empty) > > [ 65.487595][ T8299] ---[ end trace a9a5fad3ebb303b7 ]--- > > > > If io_allocate_scq_urings() fails in io_uring_create(), 'ctx->sq_data' > > is not set yet, when calling io_sq_offload_start() in io_disable_sqo_submit() > > in error path, it will lead a null-ptr-deref. > > > > The io_disable_sqo_submit() has been removed in mainline by commit > > 70aacfe66136 ("io_uring: kill sqo_dead and sqo submission halting"), > > so the bug has been eliminated in mainline, it's a fix only for stable-5.10. > > Looks fine, it got fixed differently in newer kernels, but this patch can be > safely applied to 5.10 and 5.11 stable. Thanks, now queued up. greg k-h