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 64B93C433EF for ; Tue, 17 May 2022 18:44:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352311AbiEQSoP (ORCPT ); Tue, 17 May 2022 14:44:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46652 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352336AbiEQSoM (ORCPT ); Tue, 17 May 2022 14:44:12 -0400 Received: from mail-io1-f70.google.com (mail-io1-f70.google.com [209.85.166.70]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 37DBD393D6 for ; Tue, 17 May 2022 11:44:11 -0700 (PDT) Received: by mail-io1-f70.google.com with SMTP id m205-20020a6b3fd6000000b006586ca958d2so12934314ioa.22 for ; Tue, 17 May 2022 11:44:11 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:date:in-reply-to:message-id:subject :from:to; bh=eFDTuSie96x9bOH1fl5bJ6quL4k/UvgjH4eylB8bN6w=; b=CLXLspazFRerP4Ee3MyrGp6eCFrSMU2jjb4znoO9ft+HxbrwKY7WBCh2P4Yh3vdDr8 g28tl8ske1S09rQlgo0nRBssBd2bU+6W1ttT9P4FIFwFDzJ1gD6Fu9IRYNT71X0xACyg JnVgJK7VVnj/kWz2wtabFrhaxBqlQmR+OeSNva+oMLy99Qc+WeRZlIMRzZmASDqC6Oiq VEa71iNnaCbWXwJNMnMYxu+NOlszDNAXNFamhTrH5FJPbVCIugZLztMP/QPDACFwNF34 b5c2mLwjeZKYZoIiUm0q8GCWlJ6YZMzYLbAYtPr51EQJAmOpTNQZcI1RqfIyhGzMCsBJ /RwA== X-Gm-Message-State: AOAM530ClM4fQ/r14lbz2VV4X7lS1VcFdeFn7qCgTB1AKDdPRPHDMApk IOGNQkHUrS5O/K8CNl7K6KZFngoYY+76o5azIVjQtCUGJ170 X-Google-Smtp-Source: ABdhPJzbfsX6vQgsLZ8uyfJsXF0374MKJ9O4Pk84iVIO102w4kEQwSxlbb9+nvReNx+NOoSY1FYnqSasvWn5qwBMTilLvZinZezF MIME-Version: 1.0 X-Received: by 2002:a05:6638:2393:b0:32e:319d:c7cc with SMTP id q19-20020a056638239300b0032e319dc7ccmr6263550jat.103.1652813050526; Tue, 17 May 2022 11:44:10 -0700 (PDT) Date: Tue, 17 May 2022 11:44:10 -0700 In-Reply-To: <8cf1ef4e-03b6-4da2-530f-65058c57a9d1@kernel.dk> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000c1bd6505df39865e@google.com> Subject: Re: [syzbot] BUG: unable to handle kernel NULL pointer dereference in io_do_iopoll From: syzbot To: asml.silence@gmail.com, axboe@kernel.dk, io-uring@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: BUG: unable to handle kernel NULL pointer dereference in io_do_iopoll BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 0 P4D 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 0 PID: 4077 Comm: syz-executor.0 Not tainted 5.18.0-rc2-syzkaller-00022-ga67f2fc1f9b5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffffc900056478d8 EFLAGS: 00010246 RAX: ffffffff89dad020 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: 0000000000000003 RSI: ffffc90005647950 RDI: ffff88807f0668c0 RBP: ffff88807f066901 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81ec0c20 R11: 0000000000000000 R12: 0000000000000003 R13: ffffc90005647950 R14: ffff88807f0668c0 R15: ffff88807f066938 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 000000000ba8e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: io_do_iopoll+0x262/0x1080 fs/io_uring.c:2776 io_iopoll_try_reap_events+0xba/0x158 fs/io_uring.c:2829 io_ring_ctx_wait_and_kill+0x1d9/0x327 fs/io_uring.c:10170 io_uring_release+0x42/0x46 fs/io_uring.c:10187 __fput+0x277/0x9d0 fs/file_table.c:317 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:37 [inline] do_exit+0xaff/0x2a00 kernel/exit.c:795 do_group_exit+0xd2/0x2f0 kernel/exit.c:925 get_signal+0x22df/0x24c0 kernel/signal.c:2864 arch_do_signal_or_restart+0x82/0x20f0 arch/x86/kernel/signal.c:867 exit_to_user_mode_loop kernel/entry/common.c:166 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fe34b8890e9 Code: Unable to access opcode bytes at RIP 0x7fe34b8890bf. RSP: 002b:00007fe34c997218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007fe34b99bf68 RCX: 00007fe34b8890e9 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fe34b99bf6c RBP: 00007fe34b99bf60 R08: 00007fff26bf1080 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000246 R12: 00007fe34b99bf6c R13: 00007fff26becbef R14: 00007fe34c997300 R15: 0000000000022000 Modules linked in: CR2: 0000000000000000 ---[ end trace 0000000000000000 ]--- RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffffc900056478d8 EFLAGS: 00010246 RAX: ffffffff89dad020 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: 0000000000000003 RSI: ffffc90005647950 RDI: ffff88807f0668c0 RBP: ffff88807f066901 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81ec0c20 R11: 0000000000000000 R12: 0000000000000003 R13: ffffc90005647950 R14: ffff88807f0668c0 R15: ffff88807f066938 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 000000000ba8e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Tested on: commit: a67f2fc1 io_uring: don't attempt to IOPOLL for MSG_RIN.. git tree: git://git.kernel.dk/linux-block io_uring-5.18 console output: https://syzkaller.appspot.com/x/log.txt?x=13167865f00000 kernel config: https://syzkaller.appspot.com/x/.config?x=e408a5da421f07d4 dashboard link: https://syzkaller.appspot.com/bug?extid=1a0a53300ce782f8b3ad compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 Note: no patches were applied.