INFO: task syz-executor.1:20093 blocked for more than 143 seconds. Not tainted 5.5.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D26208 20093 25206 0x80004004 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4081 schedule+0xdc/0x2b0 kernel/sched/core.c:4155 perf_event_free_task+0x54e/0x720 kernel/events/core.c:11997 copy_process+0x494a/0x7230 kernel/fork.c:2333 _do_fork+0x146/0x1090 kernel/fork.c:2421 __do_sys_clone kernel/fork.c:2576 [inline] __se_sys_clone kernel/fork.c:2557 [inline] __x64_sys_clone+0x19a/0x260 kernel/fork.c:2557 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a9e9 Code: Bad RIP value. RSP: 002b:00007f76db567c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045a9e9 RDX: 9999999999999999 RSI: 0000000000000000 RDI: 00000000e0000200 RBP: 000000000075bf20 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f76db5686d4 R13: 00000000004c1102 R14: 00000000004d4f28 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1096: #0: ffffffff899a5680 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5334 2 locks held by getty/10099: #0: ffff8880968e9090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900018db2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/10100: #0: ffff8880899f8090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900018cb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/10101: #0: ffff8880a3472090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000188b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/10102: #0: ffff88809297b090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000183b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/10103: #0: ffff888089ad1090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900018bb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/10104: #0: ffff888099d12090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900011512e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 3 locks held by kworker/u4:1/27171: #0: ffff8880ae937358 (&rq->lock){-.-.}, at: newidle_balance+0xa28/0xe80 kernel/sched/fair.c:10177 #1: ffffffff899a5680 (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:5729 #2: ffff8880ae927258 (&base->lock){-.-.}, at: lock_timer_base+0x56/0x1b0 kernel/time/timer.c:936 2 locks held by getty/5660: #0: ffff88809eff0090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900045732e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1096 Comm: khungtaskd Not tainted 5.5.0-rc4-syzkaller #0 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+0x197/0x210 lib/dump_stack.c:118 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+0xb11/0x10c0 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 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.5.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:lock_is_held include/linux/lockdep.h:361 [inline] RIP: 0010:select_task_rq_fair+0x7cb/0x1810 kernel/sched/fair.c:6362 Code: 0f 85 2d fd ff ff 48 c7 c2 c0 48 2b 88 be 9b 02 00 00 48 c7 c7 20 49 2b 88 c6 05 e6 f4 20 09 01 e8 ef 65 07 00 e9 09 fd ff ff ff ff ff ff 48 c7 c7 e0 8a 98 89 e8 e4 6b 06 00 85 c0 0f 85 e4 RSP: 0018:ffffc90000da8a78 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 1ffffffff14f39d2 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880a9a08bd4 RBP: ffffc90000da8b18 R08: 1ffff11015d2703c R09: ffffed1015d2703d R10: ffffed1015d2703c R11: ffff8880ae9381e3 R12: ffffffff882b5040 R13: ffff8880ae937340 R14: 0000000000000010 R15: ffff8880a9947000 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000045a9bf CR3: 00000000a33fe000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: select_task_rq kernel/sched/core.c:2109 [inline] try_to_wake_up+0x435/0x1a80 kernel/sched/core.c:2628 wake_up_process+0x10/0x20 kernel/sched/core.c:2668 wake_up_worker kernel/workqueue.c:836 [inline] insert_work+0x2b8/0x3b0 kernel/workqueue.c:1337 __queue_work+0x540/0x1280 kernel/workqueue.c:1486 delayed_work_timer_fn+0x5d/0x90 kernel/workqueue.c:1611 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1404 expire_timers kernel/time/timer.c:1444 [inline] __run_timers kernel/time/timer.c:1773 [inline] __run_timers kernel/time/timer.c:1740 [inline] run_timer_softirq+0x48c/0x1790 kernel/time/timer.c:1786 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1137 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61 Code: 78 1b ea f9 eb 8a cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d 54 ab 5f 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 44 ab 5f 00 fb f4 cc 55 48 89 e5 41 57 41 56 41 55 41 54 53 e8 3e ef 99 f9 e8 49 RSP: 0018:ffffc90000d3fd68 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff132669e RBX: ffff8880a9a08340 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffff8880a9a08bd4 RBP: ffffc90000d3fd98 R08: ffff8880a9a08340 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: ffffffff8a799cc0 R14: 0000000000000000 R15: 0000000000000001 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:690 default_idle_call+0x84/0xb0 kernel/sched/idle.c:94 cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x3c8/0x6e0 kernel/sched/idle.c:269 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:361 start_secondary+0x2f4/0x410 arch/x86/kernel/smpboot.c:264 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242