syzbot


INFO: task hung in fib6_rules_net_exit (3)

Status: auto-closed as invalid on 2022/01/18 22:47
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 437d, last: 403d
similar bugs (6):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in fib6_rules_net_exit 1 312d 312d 0/1 auto-closed as invalid on 2022/05/19 15:58
linux-4.19 INFO: task hung in fib6_rules_net_exit (2) 1 119d 119d 0/1 upstream: reported on 2022/08/01 01:33
upstream INFO: task hung in fib6_rules_net_exit (2) 7 703d 793d 0/24 auto-closed as invalid on 2021/03/25 09:49
upstream INFO: task hung in fib6_rules_net_exit 1 1704d 1702d 0/24 closed as dup on 2018/03/31 16:17
android-49 INFO: task hung in fib6_rules_net_exit 1 1491d 1324d 0/3 auto-closed as invalid on 2019/04/28 09:31
android-49 INFO: task hung in fib6_rules_net_exit (2) 1 1152d 1152d 0/3 auto-closed as invalid on 2020/01/31 05:34

Sample crash report:
INFO: task kworker/u4:11:18840 blocked for more than 143 seconds.
      Not tainted 5.15.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:11   state:D stack:23760 pid:18840 ppid:     2 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 context_switch kernel/sched/core.c:4940 [inline]
 __schedule+0x940/0x26f0 kernel/sched/core.c:6287
 schedule+0xd3/0x270 kernel/sched/core.c:6366
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425
 __mutex_lock_common kernel/locking/mutex.c:669 [inline]
 __mutex_lock+0xa34/0x12f0 kernel/locking/mutex.c:729
 fib6_rules_net_exit+0xe/0x50 net/ipv6/fib6_rules.c:496
 ops_exit_list+0xb0/0x160 net/core/net_namespace.c:168
 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:591
 process_one_work+0x9bf/0x16b0 kernel/workqueue.c:2297
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8b97d420 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446
3 locks held by kworker/u4:3/254:
1 lock held by in:imklog/6231:
 #0: ffff88807e9a8d70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990
2 locks held by agetty/6467:
 #0: ffff88806ef43098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:252
 #1: ffffc90001f922e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2113
2 locks held by agetty/6468:
 #0: ffff88801fa9a098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:252
 #1: ffffc90001ff42e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2113
3 locks held by kworker/0:3/6681:
4 locks held by kworker/u4:11/18840:
 #0: ffff8881447a8938 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff8881447a8938 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff8881447a8938 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
 #0: ffff8881447a8938 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:634 [inline]
 #0: ffff8881447a8938 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline]
 #0: ffff8881447a8938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x8a3/0x16b0 kernel/workqueue.c:2268
 #1: ffffc9000c5d7db0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8d7/0x16b0 kernel/workqueue.c:2272
 #2: ffffffff8d0cef50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xb00 net/core/net_namespace.c:553
 #3: ffffffff8d0e21a8 (rtnl_mutex){+.+.}-{3:3}, at: fib6_rules_net_exit+0xe/0x50 net/ipv6/fib6_rules.c:496
3 locks held by kworker/0:10/20682:
 #0: ffff888147d42538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888147d42538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff888147d42538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
 #0: ffff888147d42538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:634 [inline]
 #0: ffff888147d42538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline]
 #0: ffff888147d42538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x8a3/0x16b0 kernel/workqueue.c:2268
 #1: ffffc90005267db0 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x8d7/0x16b0 kernel/workqueue.c:2272
 #2: ffffffff8d0e21a8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4590
3 locks held by kworker/1:9/21189:
 #0: ffff888010c67d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888010c67d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff888010c67d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
 #0: ffff888010c67d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:634 [inline]
 #0: ffff888010c67d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline]
 #0: ffff888010c67d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x8a3/0x16b0 kernel/workqueue.c:2268
 #1: ffffc9000b657db0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x8d7/0x16b0 kernel/workqueue.c:2272
 #2: ffffffff8d0e21a8 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74
3 locks held by kworker/1:13/21203:
 #0: ffff888010c67d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888010c67d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff888010c67d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
 #0: ffff888010c67d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:634 [inline]
 #0: ffff888010c67d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline]
 #0: ffff888010c67d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x8a3/0x16b0 kernel/workqueue.c:2268
 #1: ffffc9000b66fdb0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x8d7/0x16b0 kernel/workqueue.c:2272
 #2: ffffffff8d0e21a8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xb/0x60 net/core/link_watch.c:251
2 locks held by kworker/1:1/8804:
2 locks held by syz-executor.0/9107:
 #0: ffffffff8d0e21a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d0e21a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3be/0xb80 net/core/rtnetlink.c:5569
 #1: ffffffff8b9867a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #1: ffffffff8b9867a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4fc/0x620 kernel/rcu/tree_exp.h:837

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xc1d/0xf50 kernel/hung_task.c:295
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8804 Comm: kworker/1:1 Not tainted 5.15.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events iterate_cleanup_work
RIP: 0010:hlock_class kernel/locking/lockdep.c:199 [inline]
RIP: 0010:mark_lock+0xf7/0x17b0 kernel/locking/lockdep.c:4571
Code: 66 81 e2 ff 1f 44 0f b7 f2 be 08 00 00 00 4c 89 f0 48 c1 f8 06 48 8d 3c c5 20 09 d0 8f e8 d1 fa 61 00 4c 0f a3 35 29 04 76 0e <0f> 83 03 01 00 00 4b 8d 04 76 48 c1 e0 06 48 05 40 0d d0 8f 48 8d
RSP: 0018:ffffc90007187840 EFLAGS: 00000047
RAX: 0000000000000001 RBX: 1ffff92000e30f0f RCX: ffffffff815a04ef
RDX: fffffbfff1fa0135 RSI: 0000000000000008 RDI: ffffffff8fd009a0
RBP: 0000000000000100 R08: 0000000000000000 R09: ffffffff8fd009a7
R10: fffffbfff1fa0134 R11: 0000000000000000 R12: 0000000000000008
R13: ffff888075068a88 R14: 000000000000040d R15: ffff888075068aa8
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f95d65df000 CR3: 000000000b68e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 mark_usage kernel/locking/lockdep.c:4514 [inline]
 __lock_acquire+0x8a7/0x54a0 kernel/locking/lockdep.c:4969
 lock_acquire kernel/locking/lockdep.c:5625 [inline]
 lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:363 [inline]
 nf_conntrack_lock net/netfilter/nf_conntrack_core.c:87 [inline]
 get_next_corpse net/netfilter/nf_conntrack_core.c:2230 [inline]
 nf_ct_iterate_cleanup+0x1c3/0x450 net/netfilter/nf_conntrack_core.c:2275
 nf_ct_iterate_cleanup_net net/netfilter/nf_conntrack_core.c:2363 [inline]
 nf_ct_iterate_cleanup_net+0x236/0x400 net/netfilter/nf_conntrack_core.c:2347
 iterate_cleanup_work+0x45/0x130 net/netfilter/nf_nat_masquerade.c:216
 process_one_work+0x9bf/0x16b0 kernel/workqueue.c:2297
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
----------------
Code disassembly (best guess):
   0:	66 81 e2 ff 1f       	and    $0x1fff,%dx
   5:	44 0f b7 f2          	movzwl %dx,%r14d
   9:	be 08 00 00 00       	mov    $0x8,%esi
   e:	4c 89 f0             	mov    %r14,%rax
  11:	48 c1 f8 06          	sar    $0x6,%rax
  15:	48 8d 3c c5 20 09 d0 	lea    -0x702ff6e0(,%rax,8),%rdi
  1c:	8f
  1d:	e8 d1 fa 61 00       	callq  0x61faf3
  22:	4c 0f a3 35 29 04 76 	bt     %r14,0xe760429(%rip)        # 0xe760453
  29:	0e
* 2a:	0f 83 03 01 00 00    	jae    0x133 <-- trapping instruction
  30:	4b 8d 04 76          	lea    (%r14,%r14,2),%rax
  34:	48 c1 e0 06          	shl    $0x6,%rax
  38:	48 05 40 0d d0 8f    	add    $0xffffffff8fd00d40,%rax
  3e:	48                   	rex.W
  3f:	8d                   	.byte 0x8d

Crashes (24):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-selinux-root 2021/09/30 03:19 upstream 02d5e016800d be530f6c .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-kasan-gce-smack-root 2021/09/16 17:17 upstream ff1ffd71d5f0 aae492f2 .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-net-kasan-gce 2021/10/20 04:56 net-next cb3dc8901ba4 466b7db1 .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-net-kasan-gce 2021/10/20 03:59 net-next cb3dc8901ba4 466b7db1 .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-net-kasan-gce 2021/10/20 03:02 net-next cb3dc8901ba4 466b7db1 .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-net-kasan-gce 2021/10/20 02:22 net-next cb3dc8901ba4 466b7db1 .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-net-kasan-gce 2021/10/20 01:00 net-next cb3dc8901ba4 466b7db1 .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-net-kasan-gce 2021/10/20 00:00 net-next cb3dc8901ba4 466b7db1 .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-net-kasan-gce 2021/10/19 21:04 net-next cb3dc8901ba4 466b7db1 .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-net-kasan-gce 2021/10/19 13:50 net-next cb3dc8901ba4 24dc29db .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-net-kasan-gce 2021/10/19 00:39 net-next f616447034a1 24dc29db .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-net-kasan-gce 2021/10/18 16:12 net-next d40dfa0cebd8 0c5d9412 .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-net-kasan-gce 2021/10/18 16:11 net-next d40dfa0cebd8 0c5d9412 .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-net-kasan-gce 2021/10/18 14:58 net-next d40dfa0cebd8 0c5d9412 .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-net-kasan-gce 2021/10/18 14:34 net-next d40dfa0cebd8 0c5d9412 .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-net-kasan-gce 2021/10/18 14:34 net-next d40dfa0cebd8 0c5d9412 .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-net-kasan-gce 2021/10/18 14:21 net-next d40dfa0cebd8 0c5d9412 .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-net-kasan-gce 2021/10/18 14:07 net-next d40dfa0cebd8 0c5d9412 .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-net-kasan-gce 2021/10/18 14:05 net-next d40dfa0cebd8 0c5d9412 .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-net-kasan-gce 2021/10/18 13:59 net-next d40dfa0cebd8 0c5d9412 .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-net-kasan-gce 2021/10/18 13:06 net-next d40dfa0cebd8 0c5d9412 .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-net-kasan-gce 2021/10/18 13:02 net-next d40dfa0cebd8 0c5d9412 .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-linux-next-kasan-gce-root 2021/10/20 22:38 linux-next 51dba6e335ff f111d03b .config log report info INFO: task hung in fib6_rules_net_exit
ci-upstream-linux-next-kasan-gce-root 2021/10/20 09:27 linux-next 51dba6e335ff 466b7db1 .config log report info INFO: task hung in fib6_rules_net_exit
* Struck through repros no longer work on HEAD.