rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=4385, q=89) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294979105-4294968602), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor353 R running task 26984 8294 8125 0x00000000 Call Trace: sched_show_task.cold+0x332/0x396 kernel/sched/core.c:5337 print_other_cpu_stall kernel/rcu/tree.c:1430 [inline] check_cpu_stall kernel/rcu/tree.c:1557 [inline] __rcu_pending kernel/rcu/tree.c:3293 [inline] rcu_pending kernel/rcu/tree.c:3336 [inline] rcu_check_callbacks.cold+0xb37/0xe19 kernel/rcu/tree.c:2682 update_process_times+0x2a/0x70 kernel/time/timer.c:1650 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:168 tick_sched_timer+0xfc/0x290 kernel/time/tick-sched.c:1278 __run_hrtimer kernel/time/hrtimer.c:1465 [inline] __hrtimer_run_queues+0x3f6/0xe60 kernel/time/hrtimer.c:1527 hrtimer_interrupt+0x326/0x9e0 kernel/time/hrtimer.c:1585 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1071 [inline] smp_apic_timer_interrupt+0x10c/0x550 arch/x86/kernel/apic/apic.c:1096 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x50/0x80 kernel/locking/spinlock.c:192 Code: c0 98 82 f1 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 31 48 83 3d 01 31 d8 01 00 74 25 fb 66 0f 1f 44 00 00 01 00 00 00 e8 26 1b 28 f9 65 8b 05 9f 8d e8 77 85 c0 74 02 5d RSP: 0018:ffff888095287810 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff13e3053 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffff8880afeeaac4 RBP: ffff8880ba12b0c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880afeea240 R13: ffff8880afeea240 R14: ffffffff8869e580 R15: ffff8880ba12b0c0 rq_unlock_irq kernel/sched/sched.h:1851 [inline] __schedule+0x15a9/0x2040 kernel/sched/core.c:3520 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 tty_open+0x5ff/0x990 drivers/tty/tty_io.c:2036 chrdev_open+0x266/0x770 fs/char_dev.c:423 do_dentry_open+0x4aa/0x1160 fs/open.c:796 do_last fs/namei.c:3421 [inline] path_openat+0x793/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_sys_open+0x3b3/0x520 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7ff2bf68caf9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff2bf63e318 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ff2bf7143e8 RCX: 00007ff2bf68caf9 RDX: 0000000000000802 RSI: 0000000020000840 RDI: ffffffffffffff9c RBP: 00007ff2bf7143e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 7974742f7665642f R13: 00007fff5904369f R14: 00007ff2bf63e400 R15: 0000000000022000 rcu: rcu_preempt kthread starved for 10538 jiffies! g4385 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29208 10 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 schedule_timeout+0x4cf/0xfe0 kernel/time/timer.c:1818 rcu_gp_kthread+0xdad/0x21c0 kernel/rcu/tree.c:2202 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 ---------------- Code disassembly (best guess), 5 bytes skipped: 0: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 7: fc ff df a: 48 c1 e8 03 shr $0x3,%rax e: 80 3c 10 00 cmpb $0x0,(%rax,%rdx,1) 12: 75 31 jne 0x45 14: 48 83 3d 01 31 d8 01 cmpq $0x0,0x1d83101(%rip) # 0x1d8311d 1b: 00 1c: 74 25 je 0x43 1e: fb sti 1f: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) * 25: bf 01 00 00 00 mov $0x1,%edi <-- trapping instruction 2a: e8 26 1b 28 f9 callq 0xf9281b55 2f: 65 8b 05 9f 8d e8 77 mov %gs:0x77e88d9f(%rip),%eax # 0x77e88dd5 36: 85 c0 test %eax,%eax 38: 74 02 je 0x3c 3a: 5d pop %rbp