rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=73a/1/0x4000000000000000 softirq=71162/71164 fqs=37 (detected by 0, t=10502 jiffies, g=111677, q=107) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3917 Comm: systemd-udevd Not tainted 5.8.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:debug_lockdep_rcu_enabled+0x23/0x30 kernel/rcu/update.c:289 Code: cc cc cc cc cc cc cc 8b 05 0a ba c9 02 85 c0 74 21 8b 05 54 eb c9 02 85 c0 74 17 65 48 8b 04 25 00 ff 01 00 8b 80 cc 08 00 00 <85> c0 0f 94 c0 0f b6 c0 c3 cc cc cc cc 53 48 c7 c3 00 6c 03 00 e8 RSP: 0018:ffffc90000da8dd0 EFLAGS: 00000002 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81640efc RDX: ffff88809e998080 RSI: ffffffff816410be RDI: 0000000000000001 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8aae594f R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: ffff8880ae727840 R14: ffff888096a17b40 R15: dffffc0000000000 FS: 00007fa7a24758c0(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000043e360 CR3: 000000009e53a000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock_held_common kernel/rcu/update.c:114 [inline] rcu_read_lock_sched_held+0xd/0xb0 kernel/rcu/update.c:133 trace_hrtimer_expire_exit include/trace/events/timer.h:279 [inline] __run_hrtimer kernel/time/hrtimer.c:1523 [inline] __hrtimer_run_queues+0xd13/0xfc0 kernel/time/hrtimer.c:1584 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1646 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0x142/0x5e0 arch/x86/kernel/apic/apic.c:1097 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:711 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] sysvec_apic_timer_interrupt+0xe0/0x120 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:596 RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:31 [inline] RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:316 [inline] RIP: 0010:rcu_is_watching+0x5d/0xb0 kernel/rcu/tree.c:1097 Code: 80 3c 11 00 75 61 48 03 1c c5 20 39 81 89 48 b8 00 00 00 00 00 fc ff df 48 8d bb d8 00 00 00 48 89 fa 48 c1 ea 03 0f b6 14 02 <48> 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 25 8b 83 d8 00 00 RSP: 0018:ffffc90001577618 EFLAGS: 00000a02 RAX: dffffc0000000000 RBX: ffff8880ae736c00 RCX: 1ffffffff1302725 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8880ae736cd8 RBP: 00007fa7a12e8335 R08: 0000000000000000 R09: ffffffff8c58fa27 R10: 0000000000000000 R11: 0000000000000000 R12: ffffc90001577700 R13: 0000000000000000 R14: ffff88809e998080 R15: 0000000000001000 rcu_read_unlock include/linux/rcupdate.h:684 [inline] is_bpf_text_address+0xdd/0x160 kernel/bpf/core.c:706 kernel_text_address kernel/extable.c:151 [inline] kernel_text_address+0xbd/0xf0 kernel/extable.c:120 __kernel_text_address+0x9/0x30 kernel/extable.c:105 unwind_get_return_address arch/x86/kernel/unwind_orc.c:317 [inline] unwind_get_return_address+0x51/0x90 arch/x86/kernel/unwind_orc.c:312 arch_stack_walk+0x97/0xf0 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123 save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc+0x17a/0x340 mm/slab.c:3665 kmalloc include/linux/slab.h:560 [inline] tomoyo_realpath_from_path+0xc3/0x620 security/tomoyo/realpath.c:254 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x212/0x3f0 security/tomoyo/file.c:822 security_inode_getattr+0xcf/0x140 security/security.c:1278 vfs_getattr fs/stat.c:121 [inline] vfs_statx+0x170/0x390 fs/stat.c:206 vfs_lstat include/linux/fs.h:3301 [inline] __do_sys_newlstat+0x91/0x110 fs/stat.c:374 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fa7a12e8335 Code: Bad RIP value. RSP: 002b:00007ffd8b0994d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000006 RAX: ffffffffffffffda RBX: 0000559ddcd0a080 RCX: 00007fa7a12e8335 RDX: 00007ffd8b099510 RSI: 00007ffd8b099510 RDI: 0000559ddcd09080 RBP: 00007ffd8b0995d0 R08: 0000559ddcf8d540 R09: 0000000000001010 R10: 0000000000000020 R11: 0000000000000246 R12: 0000559ddcd09080 R13: 0000559ddcd090a0 R14: 0000559ddcd63e9b R15: 0000559ddcd63ea0 rcu: rcu_preempt kthread starved for 10428 jiffies! g111677 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29120 10 2 0x00004000 Call Trace: context_switch kernel/sched/core.c:3453 [inline] __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178 schedule+0xd0/0x2a0 kernel/sched/core.c:4253 schedule_timeout+0x148/0x250 kernel/time/timer.c:1897 rcu_gp_fqs_loop kernel/rcu/tree.c:1874 [inline] rcu_gp_kthread+0xae5/0x1b50 kernel/rcu/tree.c:2044 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293