INFO: task syz-executor5:6552 blocked for more than 140 seconds. Not tainted 4.14.97+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D29048 6552 3106 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lru_add_drain_all_cpuslocked+0x6c/0x420 mm/swap.c:704 lru_add_drain_all+0xf/0x20 mm/swap.c:730 do_mlock+0x90/0x5d0 mm/mlock.c:673 SYSC_mlock2 mm/mlock.c:726 [inline] SyS_mlock2+0x49/0x70 mm/mlock.c:716 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task syz-executor0:6549 blocked for more than 140 seconds. Not tainted 4.14.97+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D28176 6549 1841 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lru_add_drain_all_cpuslocked+0x6c/0x420 mm/swap.c:704 lru_add_drain_all+0xf/0x20 mm/swap.c:730 do_mlock+0x90/0x5d0 mm/mlock.c:673 SYSC_mlock2 mm/mlock.c:726 [inline] SyS_mlock2+0x49/0x70 mm/mlock.c:716 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: (tasklist_lock){.+.?}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4541 1 lock held by rsyslogd/1626: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0xa6/0xc0 fs/file.c:768 2 locks held by getty/1754: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:275 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156 2 locks held by syz-executor5/6552: #0: (cpu_hotplug_lock.rw_sem){++++}, at: [] get_online_cpus include/linux/cpu.h:138 [inline] #0: (cpu_hotplug_lock.rw_sem){++++}, at: [] lru_add_drain_all+0xa/0x20 mm/swap.c:729 #1: (lock#4){+.+.}, at: [] lru_add_drain_all_cpuslocked+0x6c/0x420 mm/swap.c:704 2 locks held by syz-executor0/6549: #0: (cpu_hotplug_lock.rw_sem){++++}, at: [] get_online_cpus include/linux/cpu.h:138 [inline] #0: (cpu_hotplug_lock.rw_sem){++++}, at: [] lru_add_drain_all+0xa/0x20 mm/swap.c:729 #1: (lock#4){+.+.}, at: [] lru_add_drain_all_cpuslocked+0x6c/0x420 mm/swap.c:704 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.97+ #1 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x10e lib/dump_stack.c:53 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at pc 0xffffffffa46508a2