INFO: task syz-executor0:31887 blocked for more than 140 seconds.
      Not tainted 4.9.125+ #89
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D29688 31887   2353 0x00000004
 ffff8801a56c5f00 ffff8801d29ae880 ffff8801acdf1b80 ffff8801a0275f00
 ffff8801db721018 ffff8801d5aa7b10 ffffffff8277d092 ffffffff82ecc3a0
 ffff8801a56c5f00 ffffffff810ec84a 00fffc0000000000 ffff8801db7218f0
Call Trace:
 [<ffffffff8277e5bf>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff8222ffbc>] __lock_sock+0x13c/0x250 net/core/sock.c:2035
 [<ffffffff822301c6>] lock_sock_nested+0xf6/0x120 net/core/sock.c:2505
 [<ffffffff82458ef4>] lock_sock include/net/sock.h:1404 [inline]
 [<ffffffff82458ef4>] do_tcp_setsockopt.isra.5+0x124/0x1ca0 net/ipv4/tcp.c:2486
 [<ffffffff8245ab96>] tcp_setsockopt+0xb6/0xe0 net/ipv4/tcp.c:2760
 [<ffffffff8222a43a>] sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:2706
 [<ffffffff82227d36>] SYSC_setsockopt net/socket.c:1785 [inline]
 [<ffffffff82227d36>] SyS_setsockopt+0x166/0x260 net/socket.c:1764
 [<ffffffff8100554f>] do_syscall_64+0x19f/0x480 arch/x86/entry/common.c:282
 [<ffffffff8278c193>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/24:
 #0:  (rcu_read_lock){......}, at: [<ffffffff81309cb0>] rcu_read_unlock include/linux/rcupdate.h:927 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff81309cb0>] rcu_lock_break kernel/hung_task.c:143 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff81309cb0>] check_hung_uninterruptible_tasks kernel/hung_task.c:177 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff81309cb0>] watchdog+0x310/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff813e68fc>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
2 locks held by getty/2267:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff8278a262>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<ffffffff81cdd442>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
1 lock held by syz-executor6/5279:
 #0:  (&sig->cred_guard_mutex){+.+.+.}, at: [<ffffffff81500fb3>] prepare_bprm_creds+0x53/0x110 fs/exec.c:1369

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

NMI backtrace for cpu 1
CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.125+ #89
 ffff8801d94a7d08 ffffffff81af0ae9 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810967d0 ffff8801d94a7d40
 ffffffff81afb849 0000000000000001 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81af0ae9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81af0ae9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81afb849>] nmi_cpu_backtrace.cold.0+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81afb7dc>] nmi_trigger_cpumask_backtrace+0x12c/0x151 lib/nmi_backtrace.c:60
 [<ffffffff810968d4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff8130a04d>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff8130a04d>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8130a04d>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8130a04d>] watchdog+0x6ad/0xa20 kernel/hung_task.c:239
 [<ffffffff8113d9ad>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff8278c35c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 24703 Comm: syz-executor2 Not tainted 4.9.125+ #89
task: ffff880181e0af80 task.stack: ffff8801b6520000
RIP: 0010:[<ffffffff81309450>] 
c [<ffffffff81309450>] __sanitizer_cov_trace_pc+0x0/0x50
RSP: 0018:ffff8801b6527df8  EFLAGS: 00000246
RAX: 00000000ffffffff RBX: ffff8801b6527f58 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8130e5dd RDI: ffffffff84010440
RBP: ffff8801b6527ef0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff10036ca4fc5
R13: 00000000c000003e R14: ffffffffffffffff R15: 0000000000000000
FS:  00007f5d5fe8d700(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff07a7acb8 CR3: 00000001d1bab000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff8100497b
c 0000000000000080
c 00000000009300a8
c ffff8801b6527fb8
c
 ffff8801b6527fc0
c ffff8801b6527fd0
c 0000000041b58ab3
c ffffffff82c20e38
c
 ffffffff810043f0
c ffff8801bb903700
c c000003e000000ca
c 0000000000457099
c
Call Trace:
 [<ffffffff8100566c>] do_syscall_64+0x2bc/0x480 arch/x86/entry/common.c:273
 [<ffffffff8278c193>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
c1c 
c00 
ceb 
c81 
c4c 
c89 
cff 
ce8 
cbf 
ca2 
c1c 
c00 
ce9 
c5f 
cff 
cff 
cff 
c48 
c89 
cdf 
ce8 
c12 
ca2 
c1c 
c00 
ce9 
cf9 
cfe 
cff 
cff 
c66 
c2e 
c0f 
c1f 
c84 
c00 
c00 
c00 
c00 
c00 
c0f 
c1f 
c00 
c<55> 
c48 
c89 
ce5 
c65 
c48 
c8b 
c04 
c25 
c00 
c7e 
c01 
c00 
c65 
c8b 
c15 
c2c 
ce9 
cd0 
c7e 
c81 
c