random: crng init done
INFO: task syz-executor6:4643 blocked for more than 120 seconds.
      Not tainted 4.9.71-g319c8e1 #111
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor6   D28752  4643   3577 0x00000004
 ffff8801d17f8000 0000000000000000 ffff8801d1865a40 ffff8801da2bb000
 ffff8801db321458 ffff8801d14bf740 ffffffff83899d2b ffff8801d14bf718
 ffffffff8123905f 00ffffff838a569a ffff8801db321d28 ffff8801db321d50
Call Trace:
 [<ffffffff8389b2cf>] schedule+0x7f/0x1b0 kernel/sched/core.c:3550
 [<ffffffff838a57b0>] rwsem_down_read_failed+0x1e0/0x320 kernel/locking/rwsem-xadd.c:260
 [<ffffffff81dc47c8>] call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 [<ffffffff838a4532>] __down_read arch/x86/include/asm/rwsem.h:65 [inline]
 [<ffffffff838a4532>] down_read+0x52/0xb0 kernel/locking/rwsem.c:24
 [<ffffffff8200b415>] set_termios+0xf5/0x670 drivers/tty/tty_ioctl.c:592
 [<ffffffff8200c2c1>] tty_mode_ioctl+0x931/0x9c0 drivers/tty/tty_ioctl.c:970
 [<ffffffff8200c3f0>] n_tty_ioctl_helper+0x40/0x360 drivers/tty/tty_ioctl.c:1161
 [<ffffffff81ffffb8>] n_tty_ioctl+0x148/0x2d0 drivers/tty/n_tty.c:2437
 [<ffffffff81ff8df3>] tty_ioctl+0x733/0x2170 drivers/tty/tty_io.c:2992
 [<ffffffff815ab25a>] vfs_ioctl fs/ioctl.c:43 [inline]
 [<ffffffff815ab25a>] do_vfs_ioctl+0x1aa/0x1140 fs/ioctl.c:679
 [<ffffffff815ac27f>] SYSC_ioctl fs/ioctl.c:694 [inline]
 [<ffffffff815ac27f>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
 [<ffffffff838ab505>] entry_SYSCALL_64_fastpath+0x23/0xc6

Showing all locks held in the system:
2 locks held by khungtaskd/514:
 #0:  (rcu_read_lock){......}, at: [<ffffffff81370635>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff81370635>] watchdog+0x125/0xa70 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81235dd0>] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4336
2 locks held by getty/3296:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff838a96f2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<ffffffff82002c84>] n_tty_read+0x1f4/0x16c0 drivers/tty/n_tty.c:2133
2 locks held by syz-executor6/4643:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff838a96f2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&o_tty->termios_rwsem/1){++++.+}, at: [<ffffffff8200b415>] set_termios+0xf5/0x670 drivers/tty/tty_ioctl.c:592

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

NMI backtrace for cpu 0
CPU: 0 PID: 514 Comm: khungtaskd Not tainted 4.9.71-g319c8e1 #111
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d89d7d00 ffffffff81d91639 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810ba190 ffff8801d89d7d38
 ffffffff81d9c75d 0000000000000000 0000000000000000 ffff8801d1a5b418
Call Trace:
 [<ffffffff81d91639>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d91639>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81d9c75d>] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99
 [<ffffffff81d9c897>] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60
 [<ffffffff810ba284>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81370c00>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81370c00>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81370c00>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81370c00>] watchdog+0x6f0/0xa70 kernel/hung_task.c:239
 [<ffffffff811985ed>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838ab7aa>] ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:433
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4615 Comm: syz-executor6 Not tainted 4.9.71-g319c8e1 #111
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d183e000 task.stack: ffff8801d1190000
RIP: 0010:[<ffffffff813689fb>] 
c [<ffffffff813689fb>] __read_once_size include/linux/compiler.h:243 [inline]
RIP: 0010:[<ffffffff813689fb>] 
c [<ffffffff813689fb>] __sanitizer_cov_trace_pc+0x3b/0x50 kernel/kcov.c:105
RSP: 0018:ffff8801d1197b28  EFLAGS: 00000246
RAX: 0000000000010000 RBX: ffffc90004d5e060 RCX: ffffffff8200007c
RDX: 000000000000ffff RSI: ffffc90003842000 RDI: ffffc90004d5f260
RBP: ffff8801d1197b28 R08: 1ffff1003a307d1a R09: 0000000000000000
R10: 0000000000000003 R11: ffff8801d183e000 R12: ffffc90004d5d000
R13: 00000007e9a70270 R14: 0000000020336000 R15: ffff8801d7463db8
FS:  00007f4532cc8700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0d38c4a000 CR3: 00000001d633d000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801d1197b78
c ffffffff8200007c
c ffffffffffffeffa
c 000000000000026f
c
 0000000000000000
c ffff8801d7463b80
c 1ffff1003a232f75
c 000000000000541b
c
 ffffffffffffffe7
c ffff8801d186f200
c ffff8801d1197d70
c ffffffff81ff8df3
c
Call Trace:
 [<ffffffff8200007c>] inq_canon drivers/tty/n_tty.c:2411 [inline]
 [<ffffffff8200007c>] n_tty_ioctl+0x20c/0x2d0 drivers/tty/n_tty.c:2431
 [<ffffffff81ff8df3>] tty_ioctl+0x733/0x2170 drivers/tty/tty_io.c:2992
 [<ffffffff815ab25a>] vfs_ioctl fs/ioctl.c:43 [inline]
 [<ffffffff815ab25a>] do_vfs_ioctl+0x1aa/0x1140 fs/ioctl.c:679
 [<ffffffff815ac27f>] SYSC_ioctl fs/ioctl.c:694 [inline]
 [<ffffffff815ac27f>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
 [<ffffffff838ab505>] entry_SYSCALL_64_fastpath+0x23/0xc6
Code: 
cfc 
cca 
cca 
c7e 
c81 
ce2 
c00 
c01 
c1f 
c00 
c48 
c8b 
c4d 
c08 
c75 
c2b 
c8b 
c90 
c68 
c12 
c00 
c00 
c83 
cfa 
c02 
c75 
c20 
c48 
c8b 
cb0 
c70 
c12 
c00 
c00 
c8b 
c80 
c6c 
c12 
c00 
c00 
c48 
c8b 
c16 
c<48> 
c83 
cc2 
c01 
c48 
c39 
cd0 
c76 
c07 
c48 
c89 
c0c 
cd6 
c48 
c89 
c16 
c5d 
cc3 
c0f 
c1f 
c00 
c