rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=cde/1/0x4000000000000002 softirq=12505/12513 fqs=7 (t=10500 jiffies g=6353 q=583) rcu: rcu_preempt kthread starved for 10483 jiffies! g6353 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29032 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 1 CPU: 1 PID: 8295 Comm: syz-executor.1 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:check_kcov_mode kernel/kcov.c:79 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x22/0x50 kernel/kcov.c:102 Code: 64 02 3b 00 5b 5d c3 cc 48 8b 04 24 65 48 8b 0c 25 c0 1d 02 00 65 8b 15 b8 81 8b 7e f7 c2 00 01 1f 00 75 2c 8b 91 80 13 00 00 <83> fa 02 75 21 48 8b 91 88 13 00 00 48 8b 32 48 8d 7e 01 8b 89 84 RSP: 0018:ffffc90002197440 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffffffff81487326 RBX: ffffea0002798a40 RCX: ffff8880a7eac680 RDX: 0000000000000000 RSI: 00000000fffffffc RDI: ffffea0002798a40 RBP: ffffc90002197468 R08: 000000000003a768 R09: ffffed1015078747 R10: ffffed1015078747 R11: 0000000000000000 R12: ffff88809b79dd20 R13: dffffc0000000000 R14: 00000000fffffffc R15: ffff8880a83c3a28 free_thread_stack+0x168/0x590 kernel/fork.c:280 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:decode_frame_pointer arch/x86/kernel/unwind_frame.c:175 [inline] RIP: 0010:update_stack_state+0xa9/0x530 arch/x86/kernel/unwind_frame.c:207 Code: 4d 8d 77 38 4c 89 f0 48 c1 e8 03 80 3c 18 00 74 08 4c 89 f7 e8 d8 de 7c 00 49 8b 06 48 83 c0 10 48 89 85 78 ff ff ff 45 89 ec <41> 83 e4 01 49 f7 dc 4d 21 ec 49 83 e4 fe 4c 89 a5 70 ff ff ff 4c RSP: 0018:ffffc900021976c0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: ffffc90002197ee0 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: 0000000000000008 RSI: ffffc90002197f10 RDI: ffffc90002197820 RBP: ffffc90002197768 R08: ffffffff81659d9d R09: ffffc90002197820 R10: fffff52000432f10 R11: 0000000000000000 R12: 0000000002197f10 R13: ffffc90002197f10 R14: ffffc90002197858 R15: ffffc90002197820 unwind_next_frame+0x3f1/0x7a0 arch/x86/kernel/unwind_frame.c:311 arch_stack_walk+0xb4/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xb6/0x150 kernel/stacktrace.c:123 save_stack mm/kasan/common.c:71 [inline] set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc+0x11c/0x1b0 mm/kasan/common.c:512 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:526 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc+0x254/0x340 mm/slab.c:3665 kmalloc include/linux/slab.h:561 [inline] kzalloc include/linux/slab.h:670 [inline] tomoyo_encode2+0x273/0x5a0 security/tomoyo/realpath.c:44 tomoyo_encode security/tomoyo/realpath.c:79 [inline] tomoyo_realpath_from_path+0x769/0x7c0 security/tomoyo/realpath.c:316 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x166/0x640 security/tomoyo/file.c:723 tomoyo_file_ioctl+0x23/0x30 security/tomoyo/tomoyo.c:335 security_file_ioctl+0x6d/0xd0 security/security.c:1409 ksys_ioctl fs/ioctl.c:747 [inline] __do_sys_ioctl fs/ioctl.c:756 [inline] __se_sys_ioctl fs/ioctl.c:754 [inline] __x64_sys_ioctl+0xa3/0x120 fs/ioctl.c:754 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a4e7 Code: 48 83 c4 08 48 89 d8 5b 5d c3 66 0f 1f 84 00 00 00 00 00 48 89 e8 48 f7 d8 48 39 c3 0f 92 c0 eb 92 66 90 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 0d b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fffaf480cf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045a4e7 RDX: 00007fffaf480d00 RSI: 0000000000008933 RDI: 0000000000000004 RBP: 00000000004bfb5a R08: 0000000000000009 R09: 00007fffaf480de8 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004bfb5a R13: 0000000000000000 R14: 0000000000000003 R15: 00007fffaf480de8