rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=c2e/1/0x4000000000000000 softirq=37022/37022 fqs=1 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): (detected by 0, t=10502 jiffies, g=64185, q=12) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 17609 Comm: systemd-udevd Not tainted 5.14.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:do_raw_spin_lock+0x19/0x2b0 kernel/locking/spinlock_debug.c:111 Code: 24 eb b3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 b8 00 00 00 00 00 fc ff df 41 56 41 55 41 54 55 48 89 fd 48 83 c7 04 53 <48> 83 ec 68 48 c7 44 24 08 b3 8a b5 41 48 8d 5c 24 08 48 c7 44 24 RSP: 0018:ffffc90000fd8e00 EFLAGS: 00000082 RAX: dffffc0000000000 RBX: ffff8880309f6b40 RCX: ffffffff815a0aff RDX: 1ffff11010b50d4d RSI: 0000000000010001 RDI: ffff8880b9d423c4 RBP: ffff8880b9d423c0 R08: 0000000000000000 R09: ffffffff8fcdb8ef R10: fffffbfff1f9b71d R11: 0000000000000000 R12: 0000000000000000 R13: ffff8880b9d425c0 R14: ffff8880b9d423c0 R15: 0000000000000001 FS: 00007f7e6a5908c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005595c330a158 CR3: 00000000398ca000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1541 [inline] __hrtimer_run_queues+0x243/0xe50 kernel/time/hrtimer.c:1601 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x13/0x60 kernel/kcov.c:196 Code: 00 4d 8b 03 48 0f bd ca 49 8b 45 00 48 63 c9 e9 64 ff ff ff 0f 1f 00 65 8b 05 89 12 8d 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 <65> 48 8b 14 25 00 f0 01 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 RSP: 0018:ffffc900021973e0 EFLAGS: 00000246 RAX: 0000000080000000 RBX: 000000000000000c RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff83a683fa RDI: 0000000000000003 RBP: ffff8880299c5080 R08: 0000000000000000 R09: 000000000000000c R10: ffffffff83a683e7 R11: 0000000000000010 R12: 0000000000000026 R13: 000000000000020d R14: dffffc0000000000 R15: 0000000000000000 tomoyo_domain_quota_is_ok+0x31a/0x550 security/tomoyo/util.c:1092 tomoyo_supervisor+0x2f2/0xf00 security/tomoyo/common.c:2089 tomoyo_audit_path_number_log security/tomoyo/file.c:235 [inline] tomoyo_path_number_perm+0x419/0x590 security/tomoyo/file.c:734 tomoyo_path_mknod+0x10d/0x190 security/tomoyo/tomoyo.c:239 security_path_mknod+0xf9/0x170 security/security.c:1131 may_o_create fs/namei.c:3049 [inline] lookup_open.isra.0+0x475/0x13d0 fs/namei.c:3191 open_last_lookups fs/namei.c:3298 [inline] path_openat+0x9b3/0x27f0 fs/namei.c:3504 do_filp_open+0x1aa/0x400 fs/namei.c:3534 do_sys_openat2+0x16d/0x420 fs/open.c:1204 do_sys_open fs/open.c:1220 [inline] __do_sys_open fs/open.c:1228 [inline] __se_sys_open fs/open.c:1224 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1224 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f7e694026f0 Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d 19 30 2c 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 fe 9d 01 00 48 89 04 24 RSP: 002b:00007ffddae87528 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7e694026f0 RDX: 0000000000000180 RSI: 00000000000800c2 RDI: 00005595c32dd010 RBP: 000000000003a2f8 R08: 000000000000fefe R09: 0000000000000030 R10: 0000000000000000 R11: 0000000000000246 R12: 00005595c32dd025 R13: 8421084210842109 R14: 00000000000800c2 R15: 00007f7e69490540 task:systemd-udevd state:R running task stack:22968 pid: 4865 ppid: 1 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:4681 [inline] __schedule+0x93a/0x26f0 kernel/sched/core.c:5938 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:6326 irqentry_exit+0x31/0x80 kernel/entry/common.c:427 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:is_anon_ns fs/mount.h:147 [inline] RIP: 0010:__prepend_path fs/d_path.c:89 [inline] RIP: 0010:prepend_path+0x93c/0xdb0 fs/d_path.c:140 Code: 00 f0 ff ff e8 65 4d a0 ff 48 81 fb 00 f0 ff ff 77 3e e8 77 47 a0 ff 48 8d bb 80 00 00 00 48 89 f8 48 c1 e8 03 42 80 3c 38 00 <0f> 85 1f 04 00 00 48 8b 9b 80 00 00 00 31 ff 41 bc 01 00 00 00 48 RSP: 0018:ffffc90001827898 EFLAGS: 00000246 RAX: 1ffff110045bc210 RBX: ffff888022de1000 RCX: 0000000000000000 RDX: ffff888022678140 RSI: ffffffff81d495b9 RDI: ffff888022de1080 RBP: ffffc900018279a0 R08: fffffffffffff000 R09: 0000000000000001 R10: ffffffff81d495ab R11: 0000000000000000 R12: ffff88801803d7c0 R13: ffff88801803d7c0 R14: 0000000000000000 R15: dffffc0000000000 d_absolute_path+0xd7/0x170 fs/d_path.c:202 tomoyo_get_absolute_path security/tomoyo/realpath.c:101 [inline] tomoyo_realpath_from_path+0x288/0x620 security/tomoyo/realpath.c:276 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x21b/0x400 security/tomoyo/file.c:822 security_inode_getattr+0xcf/0x140 security/security.c:1332 vfs_getattr fs/stat.c:139 [inline] vfs_statx+0x164/0x390 fs/stat.c:207 vfs_fstatat fs/stat.c:225 [inline] vfs_lstat include/linux/fs.h:3386 [inline] __do_sys_newlstat+0x91/0x110 fs/stat.c:380 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f7e69402335 RSP: 002b:00007ffddae87568 EFLAGS: 00000246 ORIG_RAX: 0000000000000006 RAX: ffffffffffffffda RBX: 00005595c32d8070 RCX: 00007f7e69402335 RDX: 00007ffddae875a0 RSI: 00007ffddae875a0 RDI: 00005595c32d7070 RBP: 00007ffddae87660 R08: 00007f7e696c11a8 R09: 0000000000001010 R10: 00007f7e696c0b58 R11: 0000000000000246 R12: 00005595c32d7070 R13: 00005595c32d7074 R14: 00005595c32d3df1 R15: 00005595c32d3df4 rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g64185 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=41305 rcu: rcu_preempt kthread starved for 10500 jiffies! g64185 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:I stack:29096 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4681 [inline] __schedule+0x93a/0x26f0 kernel/sched/core.c:5938 schedule+0xd3/0x270 kernel/sched/core.c:6017 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop kernel/rcu/tree.c:1996 [inline] rcu_gp_kthread+0xd34/0x1980 kernel/rcu/tree.c:2169 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 0 CPU: 0 PID: 178 Comm: kworker/u4:4 Not tainted 5.14.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound toggle_allocation_gate Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_check_gp_kthread_starvation.cold+0x1d1/0x1d6 kernel/rcu/tree_stall.h:479 print_other_cpu_stall kernel/rcu/tree_stall.h:584 [inline] check_cpu_stall kernel/rcu/tree_stall.h:709 [inline] rcu_pending kernel/rcu/tree.c:3922 [inline] rcu_sched_clock_irq+0x2001/0x20c0 kernel/rcu/tree.c:2641 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1421 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1601 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline] RIP: 0010:smp_call_function_many_cond+0x452/0xc20 kernel/smp.c:967 Code: 0b 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 50 48 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 33 06 00 00 8b 43 08 31 RSP: 0018:ffffc90001877a00 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9d55dc0 RCX: 0000000000000000 RDX: ffff888013980000 RSI: ffffffff816994e0 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff81699506 R11: 0000000000000000 R12: ffffed10173aabb9 R13: 0000000000000001 R14: ffff8880b9d55dc8 R15: 0000000000000001 on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1133 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:929 [inline] text_poke_bp_batch+0x1b3/0x560 arch/x86/kernel/alternative.c:1114 text_poke_flush arch/x86/kernel/alternative.c:1268 [inline] text_poke_flush arch/x86/kernel/alternative.c:1265 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1275 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d5/0x430 kernel/jump_label.c:830 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 toggle_allocation_gate mm/kfence/core.c:623 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:615 process_one_work+0x98d/0x1630 kernel/workqueue.c:2276 worker_thread+0x658/0x11f0 kernel/workqueue.c:2422 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 24 eb and $0xeb,%al 2: b3 66 mov $0x66,%bl 4: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) b: 00 00 00 e: 0f 1f 00 nopl (%rax) 11: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 18: fc ff df 1b: 41 56 push %r14 1d: 41 55 push %r13 1f: 41 54 push %r12 21: 55 push %rbp 22: 48 89 fd mov %rdi,%rbp 25: 48 83 c7 04 add $0x4,%rdi 29: 53 push %rbx 2a: 48 83 ec 68 sub $0x68,%rsp <-- trapping instruction 2e: 48 c7 44 24 08 b3 8a movq $0x41b58ab3,0x8(%rsp) 35: b5 41 37: 48 8d 5c 24 08 lea 0x8(%rsp),%rbx 3c: 48 rex.W 3d: c7 .byte 0xc7 3e: 44 rex.R 3f: 24 .byte 0x24