All of lore.kernel.org
 help / color / mirror / Atom feed
From: syzbot <syzbot+69a90a5e8f6b59086b2a@syzkaller.appspotmail.com>
To: axboe@kernel.dk, josef@toxicpanda.com,
	linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
	nbd@other.debian.org, syzkaller-bugs@googlegroups.com
Subject: INFO: task can't die in nbd_ioctl
Date: Mon, 05 Oct 2020 00:20:16 -0700	[thread overview]
Message-ID: <00000000000061316205b0e750fc@google.com> (raw)

Hello,

syzbot found the following issue on:

HEAD commit:    de69ee6d Add linux-next specific files for 20200930
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=10d04f17900000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4919771fba5919e5
dashboard link: https://syzkaller.appspot.com/bug?extid=69a90a5e8f6b59086b2a
compiler:       gcc (GCC) 10.1.0-syz 20200507

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+69a90a5e8f6b59086b2a@syzkaller.appspotmail.com

INFO: task syz-executor.0:4417 can't die for more than 143 seconds.
task:syz-executor.0  state:D stack:28472 pid: 4417 ppid:  6852 flags:0x10004004
Call Trace:
 context_switch kernel/sched/core.c:3777 [inline]
 __schedule+0xec5/0x2200 kernel/sched/core.c:4526
 schedule+0xcf/0x270 kernel/sched/core.c:4604
 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1855
 do_wait_for_common kernel/sched/completion.c:85 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x163/0x260 kernel/sched/completion.c:138
 flush_workqueue+0x3ff/0x13e0 kernel/workqueue.c:2832
 nbd_start_device_ioctl drivers/block/nbd.c:1331 [inline]
 __nbd_ioctl drivers/block/nbd.c:1408 [inline]
 nbd_ioctl+0x76d/0xbe0 drivers/block/nbd.c:1448
 __blkdev_driver_ioctl block/ioctl.c:228 [inline]
 blkdev_ioctl+0x2a7/0x7f0 block/ioctl.c:623
 block_ioctl+0xf9/0x140 fs/block_dev.c:1866
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45dd99
Code: Bad RIP value.
RSP: 002b:00007f39f37eac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000012e80 RCX: 000000000045dd99
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000004
RBP: 000000000118bf58 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007fff8753a28f R14: 00007f39f37eb9c0 R15: 000000000118bf2c
INFO: task syz-executor.0:4417 blocked for more than 144 seconds.
      Not tainted 5.9.0-rc7-next-20200930-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:28472 pid: 4417 ppid:  6852 flags:0x10004004
Call Trace:
 context_switch kernel/sched/core.c:3777 [inline]
 __schedule+0xec5/0x2200 kernel/sched/core.c:4526
 schedule+0xcf/0x270 kernel/sched/core.c:4604
 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1855
 do_wait_for_common kernel/sched/completion.c:85 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x163/0x260 kernel/sched/completion.c:138
 flush_workqueue+0x3ff/0x13e0 kernel/workqueue.c:2832
 nbd_start_device_ioctl drivers/block/nbd.c:1331 [inline]
 __nbd_ioctl drivers/block/nbd.c:1408 [inline]
 nbd_ioctl+0x76d/0xbe0 drivers/block/nbd.c:1448
 __blkdev_driver_ioctl block/ioctl.c:228 [inline]
 blkdev_ioctl+0x2a7/0x7f0 block/ioctl.c:623
 block_ioctl+0xf9/0x140 fs/block_dev.c:1866
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45dd99
Code: Bad RIP value.
RSP: 002b:00007f39f37eac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000012e80 RCX: 000000000045dd99
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000004
RBP: 000000000118bf58 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007fff8753a28f R14: 00007f39f37eb9c0 R15: 000000000118bf2c

Showing all locks held in the system:
1 lock held by khungtaskd/1178:
 #0: ffffffff8a553d00 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6221
1 lock held by in:imklog/6557:
 #0: ffff8880a0a526b0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930
2 locks held by kworker/u5:2/6867:
 #0: ffff888093c7f138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888093c7f138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
 #0: ffff888093c7f138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
 #0: ffff888093c7f138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
 #0: ffff888093c7f138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
 #0: ffff888093c7f138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: process_one_work+0x821/0x15a0 kernel/workqueue.c:2240
 #1: ffffc900017b7da8 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x854/0x15a0 kernel/workqueue.c:2244

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 1178 Comm: khungtaskd Not tainted 5.9.0-rc7-next-20200930-syzkaller #0
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+0x198/0x1fb lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline]
 watchdog+0xd89/0xf30 kernel/hung_task.c:339
 kthread+0x3af/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 6835 Comm: syz-fuzzer Not tainted 5.9.0-rc7-next-20200930-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0033:0x415b7a
Code: 89 ac 24 c8 00 00 00 48 8d ac 24 c8 00 00 00 48 8b 94 24 e0 00 00 00 48 83 fa 08 0f 84 4d 09 00 00 48 8b 1d 98 4a 5a 01 84 03 <90> 48 8b b4 24 d8 00 00 00 48 bf 00 00 00 00 00 80 00 00 48 8d 04
RSP: 002b:000000c026e52b98 EFLAGS: 00000246
RAX: 000000c026e52c18 RBX: 00007f1f2ef8f000 RCX: 000000c000083980
RDX: 0000000000000030 RSI: 0000000000000000 RDI: 0000000000000030
RBP: 000000c026e52c60 R08: 00000000008f7880 R09: 0000000000203000
R10: 000000c011bb4cf0 R11: 0000000000000001 R12: ffffffffffffffff
R13: 0000000000000046 R14: 0000000000000045 R15: 00000000000000aa
FS:  0000000001992df0 GS:  0000000000000000


---
This report 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 issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

             reply	other threads:[~2020-10-05  7:20 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-05  7:20 syzbot [this message]
2020-10-30 19:58 ` INFO: task can't die in nbd_ioctl syzbot
2020-11-03  7:21   ` Ming Lei
2020-11-13 12:10     ` Dmitry Vyukov
2020-11-13 16:28       ` syzbot
2020-10-31 12:43 ` syzbot

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=00000000000061316205b0e750fc@google.com \
    --to=syzbot+69a90a5e8f6b59086b2a@syzkaller.appspotmail.com \
    --cc=axboe@kernel.dk \
    --cc=josef@toxicpanda.com \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=nbd@other.debian.org \
    --cc=syzkaller-bugs@googlegroups.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.