All of lore.kernel.org
 help / color / mirror / Atom feed
From: syzbot <syzbot+d12405ae80a8acdf5a9d@syzkaller.appspotmail.com>
To: davem@davemloft.net, kuba@kernel.org,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
	syzkaller-bugs@googlegroups.com
Subject: INFO: task hung in __sock_release
Date: Mon, 06 Jul 2020 08:12:23 -0700	[thread overview]
Message-ID: <00000000000049cb9905a9c74dfb@google.com> (raw)

Hello,

syzbot found the following crash on:

HEAD commit:    423b8baf Merge branch 'akpm' (patches from Andrew)
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=109ad97e100000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b3368ce0cc5f5ace
dashboard link: https://syzkaller.appspot.com/bug?extid=d12405ae80a8acdf5a9d
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)

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

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+d12405ae80a8acdf5a9d@syzkaller.appspotmail.com

INFO: task syz-executor.1:4415 blocked for more than 143 seconds.
      Not tainted 5.7.0-rc6-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D26032  4415   7163 0x80004006
Call Trace:
 context_switch kernel/sched/core.c:3367 [inline]
 __schedule+0x937/0x1ff0 kernel/sched/core.c:4083
 rwsem_down_write_slowpath+0x90a/0xf90 kernel/locking/rwsem.c:1216
 __sched_text_start+0x8/0x8
 schedule+0xd0/0x2a0 kernel/sched/core.c:4158
 rwsem_down_write_slowpath+0x706/0xf90 kernel/locking/rwsem.c:1235
 rwsem_mark_wake+0x8d0/0x8d0 include/linux/compiler.h:199
 lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934
 unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1776
 lock_release+0x800/0x800 kernel/locking/lockdep.c:4689
 __sock_release+0x280/0x280 net/socket.c:605
 __down_write kernel/locking/rwsem.c:1389 [inline]
 down_write+0x137/0x150 kernel/locking/rwsem.c:1532
 atomic64_try_cmpxchg include/asm-generic/atomic-instrumented.h:1504 [inline]
 atomic_long_try_cmpxchg_acquire include/asm-generic/atomic-long.h:442 [inline]
 __down_write kernel/locking/rwsem.c:1387 [inline]
 down_write+0xb2/0x150 kernel/locking/rwsem.c:1532
 __down_write kernel/locking/rwsem.c:1389 [inline]
 down_write+0x137/0x150 kernel/locking/rwsem.c:1532
 __down_timeout+0x2d0/0x2d0
 unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1776
 __sock_release+0x280/0x280 net/socket.c:605
 raw_release+0x53/0x730 net/can/raw.c:354
 fcntl_setlk+0xcc0/0xcc0 fs/locks.c:2542
 __sock_release+0x280/0x280 net/socket.c:605
 __sock_release+0xcd/0x280 net/socket.c:605
 sock_close+0x18/0x20 net/socket.c:1283
 __fput+0x33e/0x880 fs/file_table.c:280
 task_work_run+0xf4/0x1b0 kernel/task_work.c:123
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0xb34/0x2dd0 kernel/exit.c:796
 find_held_lock+0x2d/0x110 kernel/locking/lockdep.c:4458
 mm_update_next_owner+0x7a0/0x7a0 kernel/exit.c:375
 lock_downgrade+0x840/0x840 kernel/locking/lockdep.c:4579
 do_group_exit+0x125/0x340 kernel/exit.c:894
 get_signal+0x47b/0x24e0 kernel/signal.c:2739
 find_held_lock+0x2d/0x110 kernel/locking/lockdep.c:4458
 do_signal+0x81/0x2240 arch/x86/kernel/signal.c:784
 lock_downgrade+0x840/0x840 kernel/locking/lockdep.c:4579
 rcu_read_lock_any_held.part.0+0x50/0x50 arch/x86/include/asm/paravirt.h:754
 get_sigframe.isra.0+0x730/0x730 arch/x86/kernel/signal.c:268
 rcu_read_unlock_sched include/linux/rcupdate.h:732 [inline]
 __fd_install+0x1e6/0x600 fs/file.c:613
 __sys_socket+0x16d/0x200 net/socket.c:438
 move_addr_to_kernel+0x70/0x70 net/socket.c:195
 exit_to_usermode_loop+0x26c/0x360 arch/x86/entry/common.c:161
 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:279 [inline]
 do_syscall_64+0x6b1/0x7d0 arch/x86/entry/common.c:305
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

Showing all locks held in the system:
5 locks held by kworker/u4:4/211:
1 lock held by khungtaskd/1143:
 #0: ffffffff899bea80 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5754
1 lock held by in:imklog/6724:
 #0: ffff888092f98af0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826
3 locks held by kworker/u4:5/11846:
 #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: __write_once_size include/linux/compiler.h:226 [inline]
 #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline]
 #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline]
 #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:615 [inline]
 #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline]
 #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 kernel/workqueue.c:2239
 #1: ffffc900153dfdc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 kernel/workqueue.c:2243
 #2: ffffffff8a57aaf0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50 net/core/net_namespace.c:565
2 locks held by syz-executor.1/4415:
 #0: ffff88803f15e750 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:797 [inline]
 #0: ffff88803f15e750 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:604
 #1: ffffffff8a57aaf0 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1776

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

NMI backtrace for cpu 1
CPU: 1 PID: 1143 Comm: khungtaskd Not tainted 5.7.0-rc6-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+0x188/0x20d lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101
 lapic_can_unplug_cpu.cold+0x3b/0x3b
 nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline]
 watchdog+0xa8c/0x1010 kernel/hung_task.c:289
 reset_hung_task_detector+0x30/0x30 kernel/hung_task.c:243
 kthread+0x388/0x470 kernel/kthread.c:268
 kthread_mod_delayed_work+0x1a0/0x1a0 kernel/kthread.c:1090
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 17188 Comm: kworker/u4:6 Not tainted 5.7.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
RIP: 0010:lock_release+0x2f/0x800 kernel/locking/lockdep.c:4942
Code: 00 00 fc ff df 41 57 41 56 41 55 49 89 f5 41 54 49 89 fc 55 53 48 81 ec 98 00 00 00 48 c7 44 24 18 b3 8a b5 41 48 8d 5c 24 18 <48> c7 44 24 20 e8 c6 47 89 48 c1 eb 03 48 c7 44 24 28 40 7f 59 81
RSP: 0018:ffffc9000727fc00 EFLAGS: 00000286
RAX: ffff88809e2c4000 RBX: ffffc9000727fc18 RCX: ffffffff87b70337
RDX: dffffc0000000000 RSI: ffffffff87b700a6 RDI: ffffffff899bea80
RBP: ffff888051de4c00 R08: ffff88809e2c4000 R09: ffffed1015cc7104
R10: ffff8880ae63881b R11: ffffed1015cc7103 R12: ffffffff899bea80
R13: ffffffff87b700a6 R14: dffffc0000000000 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c0007bf6c0 CR3: 00000000a8637000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 lock_release+0x800/0x800 kernel/locking/lockdep.c:4689
 process_one_work+0x878/0x16a0 kernel/workqueue.c:2243
 lock_downgrade+0x840/0x840 kernel/locking/lockdep.c:4579
 rcu_lock_release include/linux/rcupdate.h:213 [inline]
 rcu_read_unlock include/linux/rcupdate.h:655 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:411 [inline]
 batadv_nc_worker+0x21c/0x760 net/batman-adv/network-coding.c:718
 process_one_work+0x965/0x16a0 kernel/workqueue.c:2268
 lock_release+0x800/0x800 kernel/locking/lockdep.c:4689
 pwq_dec_nr_in_flight+0x310/0x310 kernel/workqueue.c:1198
 rwlock_bug.part.0+0x90/0x90 include/linux/sched.h:1329
 worker_thread+0x96/0xe20 kernel/workqueue.c:2414
 process_one_work+0x16a0/0x16a0 kernel/workqueue.c:2273
 kthread+0x388/0x470 kernel/kthread.c:268
 kthread_mod_delayed_work+0x1a0/0x1a0 kernel/kthread.c:1090
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351


---
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.

                 reply	other threads:[~2020-07-06 15:12 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

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=00000000000049cb9905a9c74dfb@google.com \
    --to=syzbot+d12405ae80a8acdf5a9d@syzkaller.appspotmail.com \
    --cc=davem@davemloft.net \
    --cc=kuba@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.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.