syzbot


INFO: task hung in sit_exit_net

Status: auto-closed as invalid on 2019/02/22 15:09
First crash: 2206d, last: 2206d

Sample crash report:
INFO: task kworker/u4:4:6781 blocked for more than 120 seconds.
      Not tainted 4.9.92-g13b40d3 #12
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:4    D25376  6781      2 0x00000000
Workqueue: netns cleanup_net
 ffff8801d6a1e000 0000000000000000 ffff8801be9d8a80 ffffffff84429880
 ffff8801db221b98 ffff8801c4da78a8 ffffffff838a76cb 0000000000000003
 0000000000000007 00ff8801d6a1e000 ffff8801db222468 ffff8801db222490
Call Trace:
 [<ffffffff838a8c6f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3551
 [<ffffffff838a95f3>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3584
 [<ffffffff838ae392>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff838ae392>] mutex_lock_nested+0x312/0x870 kernel/locking/mutex.c:621
 [<ffffffff82f79737>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
 [<ffffffff83538a7a>] sit_exit_net+0x8a/0x600 net/ipv6/sit.c:1852
 [<ffffffff82f1d8de>] ops_exit_list.isra.4+0xae/0x150 net/core/net_namespace.c:136
 [<ffffffff82f2079d>] cleanup_net+0x31d/0x610 net/core/net_namespace.c:454
 [<ffffffff8118b1c0>] process_one_work+0x7e0/0x1610 kernel/workqueue.c:2092
 [<ffffffff8118c0d0>] worker_thread+0xe0/0x10d0 kernel/workqueue.c:2226
 [<ffffffff8119c0dd>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838b875c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373

Showing all locks held in the system:
3 locks held by kworker/0:1/25:
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff8118b0d2>] work_static include/linux/workqueue.h:186 [inline]
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff8118b0d2>] set_work_data kernel/workqueue.c:617 [inline]
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff8118b0d2>] set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff8118b0d2>] process_one_work+0x6f2/0x1610 kernel/workqueue.c:2085
 #1:  ((addr_chk_work).work){+.+...}, at: [<ffffffff8118b10c>] process_one_work+0x72c/0x1610 kernel/workqueue.c:2089
 #2:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82f79737>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
2 locks held by khungtaskd/515:
 #0:  (rcu_read_lock){......}, at: [<ffffffff813722b5>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff813722b5>] watchdog+0x125/0xa70 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81236de0>] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3662:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d316f>] __fdget_pos+0x9f/0xc0 fs/file.c:781
2 locks held by getty/3758:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff838b67a2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<ffffffff8200a8f4>] n_tty_read+0x1f4/0x16c0 drivers/tty/n_tty.c:2133
4 locks held by kworker/u4:4/6781:
 #0:  ("%s""netns"){.+.+.+}, at: [<ffffffff8118b0d2>] work_static include/linux/workqueue.h:186 [inline]
 #0:  ("%s""netns"){.+.+.+}, at: [<ffffffff8118b0d2>] set_work_data kernel/workqueue.c:617 [inline]
 #0:  ("%s""netns"){.+.+.+}, at: [<ffffffff8118b0d2>] set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0:  ("%s""netns"){.+.+.+}, at: [<ffffffff8118b0d2>] process_one_work+0x6f2/0x1610 kernel/workqueue.c:2085
 #1:  (net_cleanup_work){+.+.+.}, at: [<ffffffff8118b10c>] process_one_work+0x72c/0x1610 kernel/workqueue.c:2089
 #2:  (net_mutex){+.+.+.}, at: [<ffffffff82f205bf>] cleanup_net+0x13f/0x610 net/core/net_namespace.c:420
 #3:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82f79737>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor2/23417:
 #0:  (ipvs->sync_mutex){+.+.+.}, at: [<ffffffff831ad9c0>] do_ip_vs_set_ctl+0x240/0xc00 net/netfilter/ipvs/ip_vs_ctl.c:2402
2 locks held by syz-executor2/23424:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82f79737>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
 #1:  (ipvs->sync_mutex){+.+.+.}, at: [<ffffffff831ae067>] do_ip_vs_set_ctl+0x8e7/0xc00 net/netfilter/ipvs/ip_vs_ctl.c:2397
1 lock held by ipvs-b:7:0/23423:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82f79737>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor0/23430:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82f7e24b>] rtnl_lock net/core/rtnetlink.c:70 [inline]
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82f7e24b>] rtnetlink_rcv+0x1b/0x40 net/core/rtnetlink.c:4064
1 lock held by syz-executor0/23470:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82f7e24b>] rtnl_lock net/core/rtnetlink.c:70 [inline]
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82f7e24b>] rtnetlink_rcv+0x1b/0x40 net/core/rtnetlink.c:4064
1 lock held by syz-executor5/23435:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82f79737>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor7/23444:
 #0:  (net_mutex){+.+.+.}, at: [<ffffffff82f20be5>] copy_net_ns+0x155/0x280 net/core/net_namespace.c:387
1 lock held by syz-executor7/23478:
 #0:  (net_mutex){+.+.+.}, at: [<ffffffff82f20be5>] copy_net_ns+0x155/0x280 net/core/net_namespace.c:387

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

NMI backtrace for cpu 0
CPU: 0 PID: 515 Comm: khungtaskd Not tainted 4.9.92-g13b40d3 #12
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d9187d00 ffffffff81d95109 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810bb8f0 ffff8801d9187d38
 ffffffff81da025d 0000000000000000 0000000000000000 ffff8801d6a1e418
Call Trace:
 [<ffffffff81d95109>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d95109>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81da025d>] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99
 [<ffffffff81da0397>] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60
 [<ffffffff810bb9e4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81372880>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81372880>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81372880>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81372880>] watchdog+0x6f0/0xa70 kernel/hung_task.c:239
 [<ffffffff8119c0dd>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838b875c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.9.92-g13b40d3 #12
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d9b73000 task.stack: ffff8801d9b88000
RIP: 0010:[<ffffffff810d4541>] c [<ffffffff810d4541>] pvclock_scale_delta arch/x86/include/asm/pvclock.h:60 [inline]
RIP: 0010:[<ffffffff810d4541>] c [<ffffffff810d4541>] __pvclock_read_cycles arch/x86/include/asm/pvclock.h:94 [inline]
RIP: 0010:[<ffffffff810d4541>] c [<ffffffff810d4541>] pvclock_clocksource_read+0x191/0x4a0 arch/x86/kernel/pvclock.c:83
RSP: 0018:ffff8801db307db0  EFLAGS: 00000006
RAX: 00000108a41b93c2 RBX: ffff88021fffd040 RCX: 0000000000000001
RDX: 00000000ffffffff RSI: 00000084520dc9e1 RDI: ffff88021fffd057
RBP: ffff8801db307e38 R08: ffff88021fffd05c R09: ffff88021fffd048
R10: ffff88021fffd058 R11: ffff88021fffd050 R12: dffffc0000000000
R13: ffff88021fffd043 R14: ffffed0043fffa09 R15: ffff88021fffd05d
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000cc6000 CR3: 00000001c4fde000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff81206a7bc 0000000000000046c ffff8801d9b73000c 0000000000000000c
 0000000000000000c 0000000000000002c ffff88021fffd057c ffff88021fffd04fc
 ffffed0043fffa0bc ffff880100000006c ffffffff8448d820c ffff88021fffd05bc
Call Trace:
 [<ffffffff810d2063>] kvm_clock_read+0x23/0x40 arch/x86/kernel/kvmclock.c:91
 [<ffffffff810d2089>] kvm_clock_get_cycles+0x9/0x10 arch/x86/kernel/kvmclock.c:98
 [<ffffffff812c1e89>] tk_clock_read kernel/time/timekeeping.c:140 [inline]
 [<ffffffff812c1e89>] timekeeping_get_delta kernel/time/timekeeping.c:234 [inline]
 [<ffffffff812c1e89>] timekeeping_get_ns kernel/time/timekeeping.c:341 [inline]
 [<ffffffff812c1e89>] ktime_get+0xe9/0x1d0 kernel/time/timekeeping.c:759
 [<ffffffff812d7cee>] tick_nohz_start_idle kernel/time/tick-sched.c:563 [inline]
 [<ffffffff812d7cee>] __tick_nohz_idle_enter+0x7e/0x1180 kernel/time/tick-sched.c:929
 [<ffffffff812d9798>] tick_nohz_irq_exit+0x78/0xa0 kernel/time/tick-sched.c:995
 [<ffffffff81148491>] tick_irq_exit kernel/softirq.c:386 [inline]
 [<ffffffff81148491>] irq_exit+0x151/0x190 kernel/softirq.c:407
 [<ffffffff838bcc7b>] smp_reschedule_interrupt+0x6b/0x80 arch/x86/kernel/smp.c:270
 [<ffffffff838ba890>] reschedule_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:671
 <EOI> d [<ffffffff838b7216>] ? native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:53
 [<ffffffff838b6845>] arch_safe_halt arch/x86/include/asm/paravirt.h:104 [inline]
 [<ffffffff838b6845>] default_idle+0x55/0x360 arch/x86/kernel/process.c:295
 [<ffffffff8106bdda>] arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:286
 [<ffffffff838b7656>] default_idle_call+0x36/0x60 kernel/sched/idle.c:97
 [<ffffffff812256b0>] cpuidle_idle_call kernel/sched/idle.c:155 [inline]
 [<ffffffff812256b0>] cpu_idle_loop kernel/sched/idle.c:248 [inline]
 [<ffffffff812256b0>] cpu_startup_entry+0x2b0/0x380 kernel/sched/idle.c:303
 [<ffffffff810b08f3>] start_secondary+0x303/0x3e0 arch/x86/kernel/smpboot.c:254
Code: c48 c8b c4d cd0 c83 ce1 c07 c40 c38 cce c40 c0f c9e cc7 c40 c84 cf6 c0f c95 cc1 c40 c84 ccf c0f c85 c24 c02 c00 c00 c89 cd1 c48 c89 cc6 c48 c8b c7d ca8 cf7 cd9 c48 cd3 cee c<89> cd1 c48 cd3 ce0 c85 cd2 c8b c53 c18 c48 c0f c48 cc6 c4c c89 cde c48 c89 cf9 c48 c

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/04/03 21:52 https://android.googlesource.com/kernel/common android-4.9 13b40d327b49 676bd07e .config console log report ci-android-49-kasan-gce-386
* Struck through repros no longer work on HEAD.