INFO: task syz-executor0:8344 blocked for more than 120 seconds.
      Not tainted 4.9.84-ga9d0273 #44
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D29808  8344   3877 0x00000004
 ffff8801bb4e3000 0000000000000000 ffff8801c9e91f80 ffff8801d9b73000
 ffff8801db321b98 ffff8801b4a5fa70 ffffffff838a438b ffff8801bb4e3000
 ffffffff8114529a 00fffc0000000000 ffff8801db322468 ffff8801db322490
Call Trace:
 [<ffffffff838a592f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3550
 [<ffffffff82ee4eac>] __lock_sock+0x13c/0x260 net/core/sock.c:2035
 [<ffffffff82ee50c6>] lock_sock_nested+0xf6/0x120 net/core/sock.c:2505
 [<ffffffff83528616>] lock_sock include/net/sock.h:1404 [inline]
 [<ffffffff83528616>] ipv6_getorigdst+0x136/0x610 net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c:238
 [<ffffffff830a301a>] nf_sockopt net/netfilter/nf_sockopt.c:103 [inline]
 [<ffffffff830a301a>] nf_getsockopt+0x6a/0xc0 net/netfilter/nf_sockopt.c:121
 [<ffffffff8347934e>] ipv6_getsockopt+0x1ce/0x250 net/ipv6/ipv6_sockglue.c:1347
 [<ffffffff8322f202>] tcp_getsockopt+0x82/0xd0 net/ipv4/tcp.c:3103
 [<ffffffff82edee85>] sock_common_getsockopt+0x95/0xd0 net/core/sock.c:2665
 [<ffffffff82edc48a>] SYSC_getsockopt net/socket.c:1803 [inline]
 [<ffffffff82edc48a>] SyS_getsockopt+0x14a/0x230 net/socket.c:1785
 [<ffffffff81006504>] do_syscall_64+0x1a4/0x490 arch/x86/entry/common.c:282
 [<ffffffff838b53fd>] entry_SYSCALL_64_after_swapgs+0x47/0xc5

Showing all locks held in the system:
2 locks held by khungtaskd/514:
 #0:  (rcu_read_lock){......}, at: [<ffffffff813730a5>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff813730a5>] watchdog+0x125/0xa70 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81238190>] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3661:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d3bef>] __fdget_pos+0x9f/0xc0 fs/file.c:781
2 locks held by getty/3789:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff838b3602>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8200ab14>] n_tty_read+0x1f4/0x16c0 drivers/tty/n_tty.c:2133
1 lock held by syz-executor0/8344:
 #0:  (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff83479333>] lock_sock include/net/sock.h:1404 [inline]
 #0:  (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff83479333>] ipv6_getsockopt+0x1b3/0x250 net/ipv6/ipv6_sockglue.c:1346
1 lock held by syz-executor0/8348:
 #0:  (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff83479333>] lock_sock include/net/sock.h:1404 [inline]
 #0:  (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff83479333>] ipv6_getsockopt+0x1b3/0x250 net/ipv6/ipv6_sockglue.c:1346

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

NMI backtrace for cpu 1
CPU: 1 PID: 514 Comm: khungtaskd Not tainted 4.9.84-ga9d0273 #44
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d86dfd00 ffffffff81d956b9 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810bb190 ffff8801d86dfd38
 ffffffff81da07dd 0000000000000001 0000000000000000 ffff8801b87d0418
Call Trace:
 [<ffffffff81d956b9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d956b9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81da07dd>] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99
 [<ffffffff81da0917>] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60
 [<ffffffff810bb284>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81373670>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81373670>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81373670>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81373670>] watchdog+0x6f0/0xa70 kernel/hung_task.c:239
 [<ffffffff8119a7bd>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838b558c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:361
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.84-ga9d0273 #44
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffffffff84429880 task.stack: ffffffff84400000
RIP: 0010:[<ffffffff838b7670>] 
c [<ffffffff838b7670>] reschedule_interrupt+0x0/0xb0 arch/x86/entry/entry_64.S:658
RSP: 0018:ffffffff84407d98  EFLAGS: 00000046
RAX: 0000000000000007 RBX: ffffffff84a27c28 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff8442a12c
RBP: ffffffff84407dc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff84a36d38 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f898fc9f870 CR3: 00000001b8560000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff838b4076
c 0000000000000010
c 0000000000000246
c ffffffff84407dc0
c
 0000000000000018
c ffffffff84407df8
c ffffffff838b36a5
c ffffffff84429880
c
 0000000000000000
c ffffffff84a36d38
c 0000000000000000
c 0000000000000000
c
Call Trace:
 [<ffffffff838b36a5>] arch_safe_halt arch/x86/include/asm/paravirt.h:103 [inline]
 [<ffffffff838b36a5>] default_idle+0x55/0x360 arch/x86/kernel/process.c:295
 [<ffffffff8106bc3a>] arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:286
 [<ffffffff838b44b6>] default_idle_call+0x36/0x60 kernel/sched/idle.c:97
 [<ffffffff81226790>] cpuidle_idle_call kernel/sched/idle.c:155 [inline]
 [<ffffffff81226790>] cpu_idle_loop kernel/sched/idle.c:248 [inline]
 [<ffffffff81226790>] cpu_startup_entry+0x2b0/0x380 kernel/sched/idle.c:303
 [<ffffffff838a0fd4>] rest_init+0x184/0x190 init/main.c:408
 [<ffffffff84a6f8b6>] start_kernel+0x688/0x6bd init/main.c:663
 [<ffffffff84a6e29d>] x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:196
 [<ffffffff84a6e3df>] x86_64_start_kernel+0x140/0x163 arch/x86/kernel/head64.c:177
Code: 
c04 
c25 
cd4 
c7c 
c01 
c00 
c65 
c48 
c0f 
c44 
c24 
c25 
cd8 
c7c 
c01 
c00 
c57 
ce8 
cc1 
cb9 
c74 
cfd 
ce8 
c20 
c2a 
c00 
c00 
ce9 
c7b 
ce6 
cff 
cff 
c90 
c66 
c2e 
c0f 
c1f 
c84 
c00 
c00 
c00 
c00 
c00 
c<0f> 
c1f 
c00 
c68 
c02 
cff 
cff 
cff 
cfc 
c48 
c83 
cc4 
c88 
c4c 
c89 
c5c 
c24 
c30 
c4c 
c89 
c54 
c