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=-11.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=unavailable 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 3B587C432BE for ; Tue, 31 Aug 2021 11:05:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B3E360FE8 for ; Tue, 31 Aug 2021 11:05:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241322AbhHaLGN (ORCPT ); Tue, 31 Aug 2021 07:06:13 -0400 Received: from out30-130.freemail.mail.aliyun.com ([115.124.30.130]:52767 "EHLO out30-130.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241296AbhHaLGM (ORCPT ); Tue, 31 Aug 2021 07:06:12 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R581e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01424;MF=haoxu@linux.alibaba.com;NM=1;PH=DS;RN=19;SR=0;TI=SMTPD_---0Uml4q6e_1630407913; Received: from B-25KNML85-0107.local(mailfrom:haoxu@linux.alibaba.com fp:SMTPD_---0Uml4q6e_1630407913) by smtp.aliyun-inc.com(127.0.0.1); Tue, 31 Aug 2021 19:05:13 +0800 Subject: Re: [syzbot] general protection fault in sock_from_file To: Pavel Begunkov , Jens Axboe , syzbot , andrii@kernel.org, ast@kernel.org, bpf@vger.kernel.org, daniel@iogearbox.net, davem@davemloft.net, dvyukov@google.com, io-uring@vger.kernel.org, john.fastabend@gmail.com, kafai@fb.com, kpsingh@kernel.org, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, songliubraving@fb.com, syzkaller-bugs@googlegroups.com, yhs@fb.com References: <00000000000059117905cacce99e@google.com> <7949b7a0-fec1-34a7-aaf5-cbe07c6127ed@kernel.dk> <407ce02f-7a0a-4eb2-b242-188fc605012c@gmail.com> From: Hao Xu Message-ID: <6df81737-38d8-4c91-358a-79bc5d5f9074@linux.alibaba.com> Date: Tue, 31 Aug 2021 19:05:12 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <407ce02f-7a0a-4eb2-b242-188fc605012c@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org 在 2021/8/31 下午5:42, Pavel Begunkov 写道: > On 8/31/21 10:19 AM, Hao Xu wrote: >> 在 2021/8/31 上午10:14, Jens Axboe 写道: >>> On 8/30/21 2:45 PM, syzbot wrote: >>>> syzbot has found a reproducer for the following issue on: >>>> >>>> HEAD commit:    93717cde744f Add linux-next specific files for 20210830 >>>> git tree:       linux-next >>>> console output: https://syzkaller.appspot.com/x/log.txt?x=15200fad300000 >>>> kernel config:  https://syzkaller.appspot.com/x/.config?x=c643ef5289990dd1 >>>> dashboard link: https://syzkaller.appspot.com/bug?extid=f9704d1878e290eddf73 >>>> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1 >>>> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=111f5f9d300000 >>>> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1651a415300000 >>>> >>>> IMPORTANT: if you fix the issue, please add the following tag to the commit: >>>> Reported-by: syzbot+f9704d1878e290eddf73@syzkaller.appspotmail.com >>>> >>>> general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN >>>> KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] >>>> CPU: 0 PID: 6548 Comm: syz-executor433 Not tainted 5.14.0-next-20210830-syzkaller #0 >>>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 >>>> RIP: 0010:sock_from_file+0x20/0x90 net/socket.c:505 >>>> Code: f5 ff ff ff c3 0f 1f 44 00 00 41 54 53 48 89 fb e8 85 e9 62 fa 48 8d 7b 28 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 4f 45 31 e4 48 81 7b 28 80 f1 8a 8a 74 0c e8 58 e9 >>>> RSP: 0018:ffffc90002caf8e8 EFLAGS: 00010206 >>>> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 >>>> RDX: 0000000000000005 RSI: ffffffff8713203b RDI: 0000000000000028 >>>> RBP: ffff888019fc0780 R08: ffffffff899aee40 R09: ffffffff81e21978 >>>> R10: 0000000000000027 R11: 0000000000000009 R12: dffffc0000000000 >>>> R13: 1ffff110033f80f9 R14: 0000000000000003 R15: ffff888019fc0780 >>>> FS:  00000000013b5300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 >>>> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>>> CR2: 00000000004ae0f0 CR3: 000000001d355000 CR4: 00000000001506f0 >>>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >>>> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >>>> Call Trace: >>>>   io_sendmsg+0x98/0x640 fs/io_uring.c:4681 >>>>   io_issue_sqe+0x14de/0x6ba0 fs/io_uring.c:6578 >>>>   __io_queue_sqe+0x90/0xb50 fs/io_uring.c:6864 >>>>   io_req_task_submit+0xbf/0x1b0 fs/io_uring.c:2218 >>>>   tctx_task_work+0x166/0x610 fs/io_uring.c:2143 >>>>   task_work_run+0xdd/0x1a0 kernel/task_work.c:164 >>>>   tracehook_notify_signal include/linux/tracehook.h:212 [inline] >>>>   handle_signal_work kernel/entry/common.c:146 [inline] >>>>   exit_to_user_mode_loop kernel/entry/common.c:172 [inline] >>>>   exit_to_user_mode_prepare+0x256/0x290 kernel/entry/common.c:209 >>>>   __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] >>>>   syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 >>>>   do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 >>>>   entry_SYSCALL_64_after_hwframe+0x44/0xae >>>> RIP: 0033:0x43fd49 >>> >>> Hao, this is due to: >>> >>> commit a8295b982c46d4a7c259a4cdd58a2681929068a9 >>> Author: Hao Xu >>> Date:   Fri Aug 27 17:46:09 2021 +0800 >>> >>>      io_uring: fix failed linkchain code logic >>> >>> which causes some weirdly super long chains from that single sqe. >>> Can you take a look, please? >> Sure, I'm working on this. > > Ah, saw it after sending a patch. It's nothing too curious, just > a small error in logic. More interesting that we don't have a > test case covering it, we should definitely add something. > Saw your patch after coding my fix..😂 Since my email client doesn't receive your patch(only saw it in webpage https://lore.kernel.org/), I put my comment here: > fs/io_uring.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/fs/io_uring.c b/fs/io_uring.c > index 473a977c7979..a531c7324ea8 100644 > --- a/fs/io_uring.c > +++ b/fs/io_uring.c > @@ -6717,6 +6717,8 @@ static inline void io_queue_sqe(struct io_kiocb *req) > if (likely(!(req->flags & (REQ_F_FORCE_ASYNC | REQ_F_FAIL)))) { > __io_queue_sqe(req); > } else if (req->flags & REQ_F_FAIL) { > + /* fail all, we don't submit */ > + req->flags &= ~REQ_F_HARDLINK; maybe set REQ_F_LINK here? > io_req_complete_failed(req, req->result); > } else { > int ret = io_req_prep_async(req); > --