device lo entered promiscuous mode
device lo left promiscuous mode
INFO: task syz-executor7:30293 blocked for more than 120 seconds.
      Not tainted 4.9.68-gfb66dc2 #3
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7   D29024 30293   3593 0x20020004
 ffff8801c271e000 ffff8801c2534fc0 ffff8801cb45df80 ffff8801ca5e0000
 ffff8801db321418 ffff8801c0e2f6a0 ffffffff8389920b ffff8801c0e2f678
 ffffffff8123885f 00ffffff838a4b7a ffff8801db321ce8 ffff8801db321d10
Call Trace:
 [<ffffffff8389a7af>] schedule+0x7f/0x1b0 kernel/sched/core.c:3550
 [<ffffffff838a4c90>] rwsem_down_read_failed+0x1e0/0x320 kernel/locking/rwsem-xadd.c:260
 [<ffffffff81dc3a18>] call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 [<ffffffff838a3a12>] __down_read arch/x86/include/asm/rwsem.h:65 [inline]
 [<ffffffff838a3a12>] down_read+0x52/0xb0 kernel/locking/rwsem.c:24
 [<ffffffff8200a655>] set_termios+0xf5/0x670 drivers/tty/tty_ioctl.c:592
 [<ffffffff8200b501>] tty_mode_ioctl+0x931/0x9c0 drivers/tty/tty_ioctl.c:970
 [<ffffffff8200b630>] n_tty_ioctl_helper+0x40/0x360 drivers/tty/tty_ioctl.c:1161
 [<ffffffff81fff1f8>] n_tty_ioctl+0x148/0x2d0 drivers/tty/n_tty.c:2437
 [<ffffffff81ff8033>] tty_ioctl+0x733/0x2170 drivers/tty/tty_io.c:2992
 [<ffffffff815aa71a>] vfs_ioctl fs/ioctl.c:43 [inline]
 [<ffffffff815aa71a>] do_vfs_ioctl+0x1aa/0x1140 fs/ioctl.c:679
 [<ffffffff8167941a>] C_SYSC_ioctl fs/compat_ioctl.c:1624 [inline]
 [<ffffffff8167941a>] compat_SyS_ioctl+0x4da/0x2050 fs/compat_ioctl.c:1549
 [<ffffffff81006fc7>] do_syscall_32_irqs_on arch/x86/entry/common.c:322 [inline]
 [<ffffffff81006fc7>] do_fast_syscall_32+0x2f7/0x890 arch/x86/entry/common.c:384
 [<ffffffff838ac021>] entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:124

Showing all locks held in the system:
2 locks held by khungtaskd/514:
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136fe05>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136fe05>] watchdog+0x125/0xa70 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff812355d0>] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4336
2 locks held by getty/3306:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff838a8bd2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<ffffffff82001ec4>] n_tty_read+0x1f4/0x16c0 drivers/tty/n_tty.c:2133
2 locks held by syz-executor7/30293:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff838a8bd2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&o_tty->termios_rwsem/1){++++.+}, at: [<ffffffff8200a655>] set_termios+0xf5/0x670 drivers/tty/tty_ioctl.c:592

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

NMI backtrace for cpu 1
CPU: 1 PID: 514 Comm: khungtaskd Not tainted 4.9.68-gfb66dc2 #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d889fd00 ffffffff81d90889 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810ba1a0 ffff8801d889fd38
 ffffffff81d9b9ad 0000000000000001 0000000000000000 ffff8801c2714c18
Call Trace:
 [<ffffffff81d90889>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d90889>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81d9b9ad>] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99
 [<ffffffff81d9bae7>] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60
 [<ffffffff810ba294>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff813703d0>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff813703d0>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff813703d0>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff813703d0>] watchdog+0x6f0/0xa70 kernel/hung_task.c:239
 [<ffffffff811985ad>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838aac6a>] ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:433
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 30257 Comm: syz-executor7 Not tainted 4.9.68-gfb66dc2 #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801cf42c800 task.stack: ffff8801c1498000
RIP: 0010:[<ffffffff813681ec>] 
c [<ffffffff813681ec>] __sanitizer_cov_trace_pc+0x2c/0x60 kernel/kcov.c:68
RSP: 0018:ffff8801c149fa88  EFLAGS: 00000297
RAX: ffff8801cf42c800 RBX: ffffc900020ee060 RCX: 1ffff10038293f1c
RDX: 0000000000000000 RSI: 00000000f8500e43 RDI: ffffc900020ef260
RBP: ffff8801c149fa88 R08: 1ffff10039e85a1a R09: 0000000000000000
R10: 0000000000000003 R11: ffff8801cf42c800 R12: ffffc900020ed000
R13: 00000004f6611748 R14: 0000000020690ffc R15: ffff8801cb756838
FS:  0000000000000000(0000) GS:ffff8801db200000(0063) knlGS:00000000f773ab40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000002064a000 CR3: 00000001d1825000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801c149fad8
c ffffffff81fff2bc
c ffffffffffffeffa
c 0000000000000747
c
 0000000000000000
c ffff8801cb756600
c 1ffff10038293f61
c 000000000000541b
c
 ffffffffffffffe7
c ffff8801c3584a00
c ffff8801c149fcd0
c ffffffff81ff8033
c
Call Trace:
 [<ffffffff81fff2bc>] inq_canon drivers/tty/n_tty.c:2411 [inline]
 [<ffffffff81fff2bc>] n_tty_ioctl+0x20c/0x2d0 drivers/tty/n_tty.c:2431
 [<ffffffff81ff8033>] tty_ioctl+0x733/0x2170 drivers/tty/tty_io.c:2992
 [<ffffffff815aa71a>] vfs_ioctl fs/ioctl.c:43 [inline]
 [<ffffffff815aa71a>] do_vfs_ioctl+0x1aa/0x1140 fs/ioctl.c:679
 [<ffffffff8167941a>] C_SYSC_ioctl fs/compat_ioctl.c:1624 [inline]
 [<ffffffff8167941a>] compat_SyS_ioctl+0x4da/0x2050 fs/compat_ioctl.c:1549
 [<ffffffff81006fc7>] do_syscall_32_irqs_on arch/x86/entry/common.c:322 [inline]
 [<ffffffff81006fc7>] do_fast_syscall_32+0x2f7/0x890 arch/x86/entry/common.c:384
 [<ffffffff838ac021>] entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:124
Code: 
c65 
c48 
c8b 
c04 
c25 
c40 
c55 
c01 
c00 
c48 
c85 
cc0 
c48 
c89 
ce5 
c74 
c1a 
c65 
c8b 
c15 
cf7 
cd2 
cca 
c7e 
c81 
ce2 
c00 
c01 
c1f 
c00 
c75 
c0b 
c8b 
c90 
c68 
c12 
c00 
c00 
c83 
cfa 
c01 
c74 
c02 
c<5d> 
cc3 
c48 
c8b 
c88 
c70 
c12 
c00 
c00 
c8b 
c80 
c6c 
c12 
c00 
c00 
c48 
c8b 
c11 
c48 
c83 
cc2 
c