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=-0.7 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 E5F53C06510 for ; Tue, 2 Jul 2019 15:27:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BE59E206A3 for ; Tue, 2 Jul 2019 15:27:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726642AbfGBP1I (ORCPT ); Tue, 2 Jul 2019 11:27:08 -0400 Received: from mail-io1-f71.google.com ([209.85.166.71]:36947 "EHLO mail-io1-f71.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725780AbfGBP1H (ORCPT ); Tue, 2 Jul 2019 11:27:07 -0400 Received: by mail-io1-f71.google.com with SMTP id j18so19241790ioj.4 for ; Tue, 02 Jul 2019 08:27:06 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:message-id:subject:from:to; bh=Oirv5tvI28Y/2P5/D//E+9UIAiSWk3he7f7mxriBA74=; b=iqvqMpY9cZuAh9591t0SwZSfmTD5Dnv802JqJQcE4Q/niQGcAZFSydekX/tK4jmm3m PWhhMt0Y1TXTJtibvRXYvMtNw9MjHbM3UL/GSKEbuH5CtrZpyltM93ty/rmW3owWE2VV 5JST69BiKuBwcx7jc0JQcLhANbFKkv6IETzlB7VaBvCyqUxh1F1e7t7z5nkyuVtAjBp5 ld5qeKwzQlJG7lH5oGdQVHsEpJgIR13Tb6tdN+V7moWwvh71jmDoGem59+YYcRmuP1x5 /LpzC5bL4all2JxALE6nv8H7oXQW6+K99NHV0jHSeWDCE7w0PtwZjd3glLsv9ufGKRLw cnXA== X-Gm-Message-State: APjAAAUHpRrxtR70FbQ9/yWzkjJZtc8Jwt6T3XMwdyDL2sfIKAdutv7r DrImbitbUJR7wim9/XwRDt8aMO5PYj/befMHRGx/GGirUF5K X-Google-Smtp-Source: APXvYqxv7gu3pohlc+pqZedRwSU1QtjtXvFgV65KO/my/6TNLIFWUpJYb7nr2EHYtPwt+AXGX/E7tONzTUI3iR4Wl++AExbA3uMe MIME-Version: 1.0 X-Received: by 2002:a5d:8f99:: with SMTP id l25mr1214309iol.92.1562081226426; Tue, 02 Jul 2019 08:27:06 -0700 (PDT) Date: Tue, 02 Jul 2019 08:27:06 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000009c93d5058cb46073@google.com> Subject: INFO: task hung in blkdev_issue_flush (2) From: syzbot To: axboe@kernel.dk, idryomov@gmail.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, sagi@grimberg.me, snitzer@redhat.com, syzkaller-bugs@googlegroups.com, torvalds@linux-foundation.org, wgh@torlan.ru, zkabelac@redhat.com Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: 6fbc7275 Linux 5.2-rc7 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1218ee83a00000 kernel config: https://syzkaller.appspot.com/x/.config?x=f6451f0da3d42d53 dashboard link: https://syzkaller.appspot.com/bug?extid=e7624af9c1ef3b617512 compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13105d6da00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=120c261ba00000 The bug was bisected to: commit a32e236eb93e62a0f692e79b7c3c9636689559b9 Author: Linus Torvalds Date: Fri Aug 3 19:22:09 2018 +0000 Partially revert "block: fail op_is_write() requests to read-only partitions" bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=10fc732ba00000 final crash: https://syzkaller.appspot.com/x/report.txt?x=12fc732ba00000 console output: https://syzkaller.appspot.com/x/log.txt?x=14fc732ba00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+e7624af9c1ef3b617512@syzkaller.appspotmail.com Fixes: a32e236eb93e ("Partially revert "block: fail op_is_write() requests to read-only partitions"") INFO: task syz-executor485:8568 blocked for more than 143 seconds. Not tainted 5.2.0-rc7 #46 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor485 D28528 8568 8564 0x00004004 Call Trace: context_switch kernel/sched/core.c:2818 [inline] __schedule+0x7cb/0x1560 kernel/sched/core.c:3445 schedule+0xa8/0x260 kernel/sched/core.c:3509 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1783 io_schedule_timeout+0x26/0x80 kernel/sched/core.c:5119 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common_io kernel/sched/completion.c:121 [inline] wait_for_completion_io+0x29c/0x440 kernel/sched/completion.c:169 submit_bio_wait+0x11d/0x1c0 block/bio.c:1003 blkdev_issue_flush+0x20d/0x300 block/blk-flush.c:449 blkdev_fsync+0x95/0xd0 fs/block_dev.c:687 vfs_fsync_range+0x141/0x230 fs/sync.c:197 vfs_fsync fs/sync.c:211 [inline] do_fsync+0x54/0xa0 fs/sync.c:221 __do_sys_fdatasync fs/sync.c:234 [inline] __se_sys_fdatasync fs/sync.c:232 [inline] __x64_sys_fdatasync+0x36/0x50 fs/sync.c:232 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x449749 Code: Bad RIP value. RSP: 002b:00007fa817de2ce8 EFLAGS: 00000246 ORIG_RAX: 000000000000004b RAX: ffffffffffffffda RBX: 00000000006dac58 RCX: 0000000000449749 RDX: 0000000000449749 RSI: 0000000000000000 RDI: 0000000000000009 RBP: 00000000006dac50 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dac5c R13: 00007fff567b6b5f R14: 00007fa817de39c0 R15: 20c49ba5e353f7cf Showing all locks held in the system: 1 lock held by khungtaskd/1043: #0: 00000000f7c610b3 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5149 2 locks held by rsyslogd/8451: #0: 00000000dfc1566f (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 #1: 0000000054220207 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1168 [inline] #1: 0000000054220207 (&rq->lock){-.-.}, at: __schedule+0x1f5/0x1560 kernel/sched/core.c:3397 2 locks held by getty/8541: #0: 000000004ff543bd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000002a3905f3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8542: #0: 000000006e67fcec (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000ee71e4f3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8543: #0: 00000000bd0907a0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000000876abce (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8544: #0: 00000000710d6f7d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000af289586 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8545: #0: 000000003399e62d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000ee97f91a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8546: #0: 00000000ff2274c6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000b96c5a9f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8547: #0: 000000005165f028 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000e89d5b4a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1043 Comm: khungtaskd Not tainted 5.2.0-rc7 #46 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0x9b7/0xec0 kernel/hung_task.c:289 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60 --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches