PF_BRIDGE: RTM_NEWNEIGH with invalid ifindex
blk_update_request: I/O error, dev loop0, sector 0
Buffer I/O error on dev loop0, logical block 0, lost async page write
INFO: task syz-executor2:5404 blocked for more than 120 seconds.
      Not tainted 4.9.95-g13cc540 #5
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor2   D28912  5404   3857 0x20020004
 ffff8801cd193000 ffff8801bf120000 ffff8801d9679f80 ffff8801a6a14800
 ffff8801db321b98 ffff8801c131fa90 ffffffff839e140d 1ffff10038263f46
 ffffffff85341f38 0000000041b58ab3 00ffffff841c03f8 ffff8801db322468
Call Trace:
 [<ffffffff839e2a0f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff839eee21>] schedule_timeout+0x861/0xf70 kernel/time/timer.c:1768
 [<ffffffff839e0bea>] io_schedule_timeout+0x1ba/0x390 kernel/sched/core.c:5180
 [<ffffffff839e4343>] do_wait_for_common kernel/sched/completion.c:75 [inline]
 [<ffffffff839e4343>] __wait_for_common kernel/sched/completion.c:93 [inline]
 [<ffffffff839e4343>] wait_for_common_io kernel/sched/completion.c:107 [inline]
 [<ffffffff839e4343>] wait_for_completion_io+0x203/0x2e0 kernel/sched/completion.c:155
 [<ffffffff81df83a2>] submit_bio_wait+0x112/0x180 block/bio.c:885
 [<ffffffff81e2aaf2>] blkdev_issue_flush+0x152/0x220 block/blk-flush.c:518
 [<ffffffff8162c7f5>] blkdev_fsync+0x85/0xb0 fs/block_dev.c:378
 [<ffffffff81617dfc>] vfs_fsync_range+0x10c/0x260 fs/sync.c:195
 [<ffffffff81617fc2>] vfs_fsync fs/sync.c:209 [inline]
 [<ffffffff81617fc2>] do_fsync+0x42/0xb0 fs/sync.c:219
 [<ffffffff81618746>] SYSC_fsync fs/sync.c:228 [inline]
 [<ffffffff81618746>] SyS_fsync+0x16/0x20 fs/sync.c:226
 [<ffffffff81006da7>] do_syscall_32_irqs_on arch/x86/entry/common.c:325 [inline]
 [<ffffffff81006da7>] do_fast_syscall_32+0x2f7/0x870 arch/x86/entry/common.c:387
 [<ffffffff839f3a10>] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137

Showing all locks held in the system:
2 locks held by khungtaskd/518:
 #0:  (rcu_read_lock){......}, at: [<ffffffff813646bc>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff813646bc>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81423cb0>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3676:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d575c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/3772:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f04b2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8211c722>] n_tty_read+0x202/0x16b0 drivers/tty/n_tty.c:2133

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

NMI backtrace for cpu 0
CPU: 0 PID: 518 Comm: khungtaskd Not tainted 4.9.95-g13cc540 #5
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d86ffd08 ffffffff81eb0ba9 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810b7d60 ffff8801d86ffd40
 ffffffff81ebbed7 0000000000000000 0000000000000000 0000000000000002
Call Trace:
 [<ffffffff81eb0ba9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb0ba9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebbed7>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebbe6a>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810b7e64>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81364c54>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81364c54>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81364c54>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81364c54>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119ad2d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f24dc>] 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 4.9.95-g13cc540 #5
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d9b73000 task.stack: ffff8801d9b88000
RIP: 0010:[<ffffffff81235234>] 
c [<ffffffff81235234>] hlock_class kernel/locking/lockdep.c:149 [inline]
RIP: 0010:[<ffffffff81235234>] 
c [<ffffffff81235234>] lookup_chain_cache kernel/locking/lockdep.c:2122 [inline]
RIP: 0010:[<ffffffff81235234>] 
c [<ffffffff81235234>] validate_chain kernel/locking/lockdep.c:2236 [inline]
RIP: 0010:[<ffffffff81235234>] 
c [<ffffffff81235234>] __lock_acquire+0xee4/0x4070 kernel/locking/lockdep.c:3345
RSP: 0018:ffff8801db307d10  EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff8801d9b738c8 RCX: 00000000ffffffd1
RDX: 1ffff1003b36e71d RSI: ffff8801d9b738c8 RDI: 0000000000000000
RBP: ffff8801db307eb8 R08: ffff8801d9b738e8 R09: 0000000000000001
R10: ffff8801d9b73000 R11: 0000000000000001 R12: 000000000000002f
R13: 0000000000000000 R14: 000000002abc0a8d R15: 7ef8ab1144cb32c8
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f18619c8000 CR3: 00000001c4dd6000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff81234350
c 000000000000000b
c ffff8801db318558
c 0000000c00000008
c
 0000000b00000020
c ffff8801db307d78
c ffffffff81f1863b
c ffff8801d9b738c0
c
 ffff8801d9b738c8
c 0000000000000246
c 000000000000dcea
c ffffffff81205a52
c
Call Trace:
 [<ffffffff81238e30>] lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756
 [<ffffffff812b529a>] seqcount_lockdep_reader_access include/linux/seqlock.h:80 [inline]
 [<ffffffff812b529a>] read_seqcount_begin include/linux/seqlock.h:163 [inline]
 [<ffffffff812b529a>] ktime_get+0x11a/0x1e0 kernel/time/timekeeping.c:757
 [<ffffffff812cc8ec>] tick_nohz_irq_enter kernel/time/tick-sched.c:1144 [inline]
 [<ffffffff812cc8ec>] tick_irq_enter+0xcc/0x220 kernel/time/tick-sched.c:1165
 [<ffffffff81148ed3>] irq_enter+0xb3/0xd0 kernel/softirq.c:345
 [<ffffffff839f6a3a>] smp_reschedule_interrupt+0xa/0x90 arch/x86/kernel/smp.c:267
 [<ffffffff839f4610>] reschedule_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:671
 <EOI> 
d [<ffffffff839f0f16>] ? native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:53
 [<ffffffff839f0555>] arch_safe_halt arch/x86/include/asm/paravirt.h:104 [inline]
 [<ffffffff839f0555>] default_idle+0x55/0x360 arch/x86/kernel/process.c:295
 [<ffffffff81069fa0>] arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:286
 [<ffffffff839f1375>] default_idle_call+0x45/0x60 kernel/sched/idle.c:97
 [<ffffffff81220e35>] cpuidle_idle_call kernel/sched/idle.c:155 [inline]
 [<ffffffff81220e35>] cpu_idle_loop kernel/sched/idle.c:248 [inline]
 [<ffffffff81220e35>] cpu_startup_entry+0x2b5/0x380 kernel/sched/idle.c:303
 [<ffffffff810ad1f3>] start_secondary+0x323/0x400 arch/x86/kernel/smpboot.c:254
Code: 
c00 
c00 
c0f 
c84 
c0b 
c04 
c00 
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c48 
cb8 
c00 
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cfc 
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cdf 
c48 
c8b 
c54 
c24 
c78 
c48 
cc1 
cea 
c03 
c0f 
cb6 
c04 
c02 
c84 
cc0 
c74 
c08 
c3c 
c03 
c0f 
c8e 
c60 
c2f 
c00 
c00 
c<44> 
c0f 
cb7 
c63 
c20 
c41 
c81 
ce4 
cff 
c1f 
c00 
c00 
c4d 
c69 
ce4 
cb0 
c01 
c00 
c00 
c49 
c81 
c