INFO: task syz-executor.2:22168 blocked for more than 143 seconds. Not tainted 5.3.0-rc1+ #76 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D25560 22168 8833 0x20024004 Call Trace: context_switch kernel/sched/core.c:3254 [inline] __schedule+0x755/0x1580 kernel/sched/core.c:3880 schedule+0xa8/0x270 kernel/sched/core.c:3944 perf_event_free_task+0x50d/0x6d0 kernel/events/core.c:11606 copy_process+0x45d4/0x6b00 kernel/fork.c:2283 _do_fork+0x146/0xfa0 kernel/fork.c:2369 __do_compat_sys_x86_clone arch/x86/ia32/sys_ia32.c:253 [inline] __se_compat_sys_x86_clone arch/x86/ia32/sys_ia32.c:236 [inline] __ia32_compat_sys_x86_clone+0x188/0x260 arch/x86/ia32/sys_ia32.c:236 do_syscall_32_irqs_on arch/x86/entry/common.c:332 [inline] do_fast_syscall_32+0x27b/0xdb3 arch/x86/entry/common.c:403 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f1e9c9 Code: Bad RIP value. RSP: 002b:00000000f5d1a0cc EFLAGS: 00000296 ORIG_RAX: 0000000000000078 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000099999999 RSI: 0000000000000000 RDI: 00000000ffffffff RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/1055: #0: 0000000011d71caf (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5257 2 locks held by kworker/u4:5/3045: #0: 00000000ef453056 (&rq->lock){-.-.}, at: idle_balance kernel/sched/fair.c:9815 [inline] #0: 00000000ef453056 (&rq->lock){-.-.}, at: pick_next_task_fair+0xc42/0x1a50 kernel/sched/fair.c:6852 #1: 0000000011d71caf (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:5820 1 lock held by rsyslogd/8656: 2 locks held by getty/8746: #0: 0000000063e8ed18 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000f64584fa (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8747: #0: 000000005fae386e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000009f304c38 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8748: #0: 0000000009bdc551 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000008f14e62e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8749: #0: 000000003b8a6491 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000159ea407 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8750: #0: 0000000094fb7c63 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000a33c7e39 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8751: #0: 000000006023a0e0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000034a2e63c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8752: #0: 0000000045c7503e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000043377bca (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1055 Comm: khungtaskd Not tainted 5.3.0-rc1+ #76 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0x9d0/0xef0 kernel/hung_task.c:289 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60