rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 1-...!: (1 GPs behind) idle=01d/1/0x4000000000000000 softirq=7937/7940 fqs=1
(t=10501 jiffies g=9161 q=146)
rcu: rcu_preempt kthread starved for 10500 jiffies! g9161 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:
task:rcu_preempt state:R running task stack:28016 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4520 Comm: syz.0.59 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x60 kernel/kcov.c:209
Code: 8b 15 c5 26 89 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 34 16 00 00 00 74 2c 8b 91 10 16 00 00 83 fa 02 75 21 <48> 8b 91 18 16 00 00 48 8b 32 48 8d 7e 01 8b 89 14 16 00 00 48 39
RSP: 0018:ffffc90003357a28 EFLAGS: 00000046
RAX: ffffffff81694e0c RBX: 0000000000a92b20 RCX: ffff888018391dc0
RDX: 0000000000000002 RSI: 000001fb6cfa72cd RDI: 0000000000a92b20
RBP: 00000000000093d4 R08: ffffffff8d8a06ef R09: 1ffffffff1b140dd
R10: dffffc0000000000 R11: fffffbfff1b140de R12: ffffffffff56d4df
R13: 00000068c77389bc R14: 1fffffffffffffff R15: 000001fb6cfa72cd
FS: 00007f879f7966c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 000000005fb70000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
timekeeping_get_delta kernel/time/timekeeping.c:273 [inline]
timekeeping_get_ns kernel/time/timekeeping.c:388 [inline]
ktime_get+0x18c/0x270 kernel/time/timekeeping.c:831
clockevents_program_event+0xe2/0x310 kernel/time/clockevents.c:326
hrtimer_start_range_ns+0xa9a/0xc20 kernel/time/hrtimer.c:1287
posixtimer_rearm+0x131/0x340 kernel/time/posix-timers.c:329
dequeue_signal+0x174/0x440 kernel/signal.c:696
get_signal+0x70a/0x12d0 kernel/signal.c:2781
arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f87a153ce57
Code: 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89
RSP: 002b:00007f879f796028 EFLAGS: 00000246
RAX: 0000000000000048 RBX: 00007f87a17b5fa0 RCX: 00007f87a153ce59
RDX: 0000200000000280 RSI: 0000000000000026 RDI: 0000000000000003
RBP: 00007f87a15d2d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f87a17b6038 R14: 00007f87a17b5fa0 R15: 00007ffcbcced7a8
NMI backtrace for cpu 1
CPU: 1 PID: 4523 Comm: syz.3.58 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
rcu_dump_cpu_stacks+0x22f/0x380 kernel/rcu/tree_stall.h:349
print_cpu_stall+0x31d/0x5f0 kernel/rcu/tree_stall.h:633
check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
rcu_pending kernel/rcu/tree.c:3936 [inline]
rcu_sched_clock_irq+0x6ea/0x1120 kernel/rcu/tree.c:2619
update_process_times+0x193/0x200 kernel/time/timer.c:2021
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x4b4/0xb70 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:35 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:106 [inline]
RIP: 0010:__local_bh_disable_ip+0x8e/0x1a0 kernel/softirq.c:328
Code: f8 f3 f3 f3 65 8b 05 19 13 b9 7e a9 00 00 0f 00 0f 85 f5 00 00 00 43 c6 44 3c 08 00 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 <4c> 8b 74 24 40 43 c6 44 3c 08 f8 fa 65 01 1d e7 12 b9 7e 65 8b 05
RSP: 0018:ffffc90003367bc0 EFLAGS: 00000246
RAX: 0000000080000000 RBX: 0000000000000200 RCX: 0000000000080000
RDX: ffffc9000eb3b000 RSI: 0000000000000200 RDI: ffffffff812c3125
RBP: ffffc90003367c78 R08: ffffffff8d8a06ef R09: 1ffffffff1b140dd
R10: dffffc0000000000 R11: fffffbfff1b140de R12: 1ffff9200066cf78
R13: 1ffff9200066cfff R14: ffff888018397280 R15: dffffc0000000000
fpregs_lock arch/x86/include/asm/fpu/api.h:70 [inline]
fpu__clear_user_states+0x3e/0x260 arch/x86/kernel/fpu/core.c:361
handle_signal arch/x86/kernel/signal.c:840 [inline]
arch_do_signal_or_restart+0xec1/0x12c0 arch/x86/kernel/signal.c:869
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fed0cb523d0
Code: 83 c0 16 83 e0 f7 74 12 50 48 8d 3d aa 1c 07 00 e8 65 65 f9 ff 0f 1f 44 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <83> ff 21 74 0b c3 66 2e 0f 1f 84 00 00 00 00 00 55 53 48 89 f3 48
RSP: 002b:00007fed0ad8ba78 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007fed0cdabfa0 RCX: 00007fed0cb32e59
RDX: 00007fed0ad8ba80 RSI: 00007fed0ad8bbb0 RDI: 0000000000000021
RBP: 00007fed0cbc8d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fed0cdac038 R14: 00007fed0cdabfa0 R15: 00007ffd55ef3b48