INFO: task syz-executor5:4061 blocked for more than 140 seconds. Not tainted 4.9.124+ #86 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D29112 4061 9740 0x00000004 ffff8801d49297c0 ffff8801a8d3bc80 ffff8801bbccf900 ffff8801924617c0 ffff8801db620fd8 ffff880196e77cf8 ffffffff8277c6a2 0000000000000000 ffff8801d492a070 ffffed003a92540d 00ff8801d49297c0 ffff8801db6218b0 Call Trace: [] schedule+0x7f/0x1b0 kernel/sched/core.c:3553 [] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3586 [] __mutex_lock_common kernel/locking/mutex.c:582 [inline] [] mutex_lock_nested+0x326/0x870 kernel/locking/mutex.c:621 [] evdev_flush+0x72/0x120 drivers/input/evdev.c:350 [] filp_close+0xa7/0x140 fs/open.c:1129 [] __close_fd+0x156/0x230 fs/file.c:651 [] SYSC_close fs/open.c:1148 [inline] [] SyS_close+0x4c/0x90 fs/open.c:1146 [] do_syscall_64+0x19f/0x480 arch/x86/entry/common.c:282 [] 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: [] rcu_read_unlock include/linux/rcupdate.h:927 [inline] #0: (rcu_read_lock){......}, at: [] rcu_lock_break kernel/hung_task.c:143 [inline] #0: (rcu_read_lock){......}, at: [] check_hung_uninterruptible_tasks kernel/hung_task.c:177 [inline] #0: (rcu_read_lock){......}, at: [] watchdog+0x310/0xa20 kernel/hung_task.c:239 #1: (tasklist_lock){.+.+..}, at: [] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336 2 locks held by getty/2220: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.+.}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 1 lock held by syz-executor5/4061: #0: (&evdev->mutex){+.+.+.}, at: [] evdev_flush+0x72/0x120 drivers/input/evdev.c:350 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.124+ #86 ffff8801d94a7d08 ffffffff81af03d9 0000000000000000 0000000000000000 0000000000000000 0000000000000001 ffffffff81096730 ffff8801d94a7d40 ffffffff81afb139 0000000000000000 0000000000000000 0000000000000003 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] nmi_cpu_backtrace.cold.0+0x48/0x87 lib/nmi_backtrace.c:99 [] nmi_trigger_cpumask_backtrace+0x12c/0x151 lib/nmi_backtrace.c:60 [] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [] check_hung_task kernel/hung_task.c:125 [inline] [] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline] [] watchdog+0x6ad/0xa20 kernel/hung_task.c:239 [] kthread+0x26d/0x300 kernel/kthread.c:211 [] 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: 20014 Comm: syz-executor3 Not tainted 4.9.124+ #86 task: ffff8801924617c0 task.stack: ffff88018bb70000 RIP: 0010:[] c [] trace_hardirqs_off_thunk+0x4/0x1c RSP: 0018:ffff88018bb77ff0 EFLAGS: 00000046 RAX: 00000000000000ca RBX: 00000000009300a8 RCX: 0000000000457099 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00000000009300a8 RBP: ffff88018bb77ff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000009300ac R13: 0000000000a3fb9f R14: 00007fd2013789c0 R15: 0000000000000000 FS: 00007fd201378700(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020a5d000 CR3: 00000001b8cd0000 CR4: 00000000001606b0 Stack: 00000000009300a0c ffffffff8278b74dc Call Trace: [] entry_SYSCALL_64_after_swapgs+0x17/0xdb Code: cfc cff cff c90 c90 c90 c90 c90 c90 c90 c90 c55 c48 c89 ce5 c57 c56 c52 c51 c50 c41 c50 c41 c51 c41 c52 c41 c53 c48 c8b c7d c08 ce8 c06 cc7 c1f c00 ceb c64 c55 c48 c89 ce5 c<57> c56 c52 c51 c50 c41 c50 c41 c51 c41 c52 c41 c53 c48 c8b c7d c08 ce8 c6a c5b c1f c