rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10500 ticks this GP) idle=ce6/1/0x4000000000000002 softirq=11237/11237 fqs=40 (t=10501 jiffies g=6889 q=69) rcu: rcu_preempt kthread starved for 10422 jiffies! g6889 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29104 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081 schedule+0x181/0x210 kernel/sched/core.c:4155 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline] rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 NMI backtrace for cpu 0 CPU: 0 PID: 8289 Comm: udevd Not tainted 5.4.0-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+0x1fb/0x318 lib/dump_stack.c:118 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x15a/0x220 kernel/rcu/tree_stall.h:254 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline] check_cpu_stall kernel/rcu/tree_stall.h:529 [inline] rcu_pending kernel/rcu/tree.c:2827 [inline] rcu_sched_clock_irq+0xe25/0x1ad0 kernel/rcu/tree.c:2271 update_process_times+0x12d/0x180 kernel/time/timer.c:1726 tick_sched_handle kernel/time/tick-sched.c:167 [inline] tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310 __run_hrtimer kernel/time/hrtimer.c:1514 [inline] __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1576 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1638 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:free_thread_stack+0x16d/0x590 kernel/fork.c:284 Code: c3 08 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 25 a4 69 00 48 8b 3b be fc ff ff ff e8 28 04 00 00 43 80 3c 2e 00 <74> 08 4c 89 e7 e8 09 a4 69 00 49 8b 1c 24 48 83 c3 08 48 89 d8 48 RSP: 0018:ffffc90002527758 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffffffff81487433 RBX: ffff8880a7854688 RCX: ffff8880a9684540 RDX: 0000000000000000 RSI: 00000000fffffffc RDI: ffffea0002a65940 RBP: ffffc90002527790 R08: dffffc0000000000 R09: fffffbfff120248a R10: fffffbfff120248a R11: 0000000000000000 R12: ffff8880a7854720 R13: dffffc0000000000 R14: 1ffff11014f0a8e4 R15: ffff8880a8b8b6a8 release_task_stack kernel/fork.c:440 [inline] put_task_stack+0xa3/0x130 kernel/fork.c:451 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256 context_switch kernel/sched/core.c:3388 [inline] __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081 preempt_schedule_irq+0xc1/0x140 kernel/sched/core.c:4338 retint_kernel+0x1b/0x2b RIP: 0010:tomoyo_scan_bprm security/tomoyo/condition.c:138 [inline] RIP: 0010:tomoyo_condition+0x1c0d/0x2950 security/tomoyo/condition.c:1120 Code: 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 ef e8 4a c9 5d fe 49 8b 5d 00 4c 89 7c 24 38 4c 01 fb 48 89 d8 48 c1 e8 03 42 8a 04 20 <84> c0 0f 85 a0 06 00 00 44 8a 23 41 0f b6 dc 31 ff 89 de e8 9b 54 RSP: 0018:ffffc900025279a0 EFLAGS: 00000a06 ORIG_RAX: ffffffffffffff13 RAX: 1ffff1100d85b500 RBX: ffff88806c2daf3b RCX: ffff8880a9684540 RDX: 0000000000000000 RSI: 000000000000004b RDI: 000000000000005e RBP: ffffc90002527b18 R08: ffffffff83544ad4 R09: ffffffff8355e67c R10: ffff8880a9684540 R11: 0000000000000002 R12: dffffc0000000000 R13: ffff8880a3ad3918 R14: 0000000000000006 R15: 0000000000000f3b tomoyo_check_acl+0x17b/0x3a0 security/tomoyo/domain.c:174 tomoyo_execute_permission+0x138/0x3f0 security/tomoyo/file.c:615 tomoyo_find_next_domain+0x3a7/0x1ca0 security/tomoyo/domain.c:749 tomoyo_bprm_check_security+0xe3/0x130 security/tomoyo/tomoyo.c:107 security_bprm_check+0x55/0xb0 security/security.c:784 search_binary_handler+0x6a/0x660 fs/exec.c:1645 exec_binprm fs/exec.c:1701 [inline] __do_execve_file+0x1573/0x1cd0 fs/exec.c:1821 do_execveat_common fs/exec.c:1867 [inline] do_execve fs/exec.c:1884 [inline] __do_sys_execve fs/exec.c:1960 [inline] __se_sys_execve fs/exec.c:1955 [inline] __x64_sys_execve+0x94/0xb0 fs/exec.c:1955 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fd8ae250207 Code: 77 19 f4 48 89 d7 44 89 c0 0f 05 48 3d 00 f0 ff ff 76 e0 f7 d8 64 41 89 01 eb d8 f7 d8 64 41 89 01 eb df b8 3b 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 02 f3 c3 48 8b 15 00 8c 2d 00 f7 d8 64 89 02 RSP: 002b:00007fff9cf7d7f8 EFLAGS: 00000202 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007fd8ae250207 RDX: 0000000001783ad0 RSI: 00007fff9cf7d8f0 RDI: 00007fff9cf7e900 RBP: 0000000000625500 R08: 0000000000001eed R09: 0000000000001eed R10: 0000000000000000 R11: 0000000000000202 R12: 0000000001783ad0 R13: 0000000000000007 R14: 0000000001782250 R15: 0000000000000005