rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 1-...!: (10500 ticks this GP) idle=22d/1/0x4000000000000000 softirq=6563/6565 fqs=8
(t=10502 jiffies g=7173 q=190)
rcu: rcu_preempt kthread starved for 10487 jiffies! g7173 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:27416 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:1914
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: 4368 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:226 [inline]
RIP: 0010:__sanitizer_cov_trace_cmp8+0x4/0x80 kernel/kcov.c:273
Code: 77 22 89 ff 89 f6 4a c7 44 02 08 04 00 00 00 4a 89 7c 02 10 4a 89 74 02 18 4a 89 44 02 20 48 ff c1 48 89 0a c3 90 48 8b 04 24 <65> 48 8b 0d 34 4e 89 7e 65 8b 15 35 4e 89 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc90000007e30 EFLAGS: 00000807
RAX: ffffffff8169844c RBX: 000001fb63109b96 RCX: ffff88807b6cbb80
RDX: 0000000000010000 RSI: 1fffffffffffffff RDI: fffffffffeab7631
RBP: 00000000015489ce R08: ffffffff8d89d8af R09: 1ffffffff1b13b15
R10: dffffc0000000000 R11: fffffbfff1b13b16 R12: 0000005d3e7a8b44
R13: 1fffffffffffffff R14: fffffffffeab7631 R15: dffffc0000000000
FS: 0000555589f0e500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 00000000758bf000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
timekeeping_get_delta kernel/time/timekeeping.c:267 [inline]
timekeeping_get_ns kernel/time/timekeeping.c:388 [inline]
ktime_get_update_offsets_now+0x17c/0x3e0 kernel/time/timekeeping.c:2303
hrtimer_update_base kernel/time/hrtimer.c:621 [inline]
hrtimer_interrupt+0x130/0x8d0 kernel/time/hrtimer.c:1793
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:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: 00 00 00 66 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 4e 2c 98 f7 48 89 df e8 86 04 99 f7 e8 11 f3 b9 f7 fb bf 01 00 00 00 06 0b 8d f7 65 8b 05 87 17 3d 76 85 c0 74 02 5b c3 e8 d4 24 3b
RSP: 0018:ffffc900034efbc0 EFLAGS: 00000282
RAX: 485f010d4336f400 RBX: ffff88802c502e40 RCX: 485f010d4336f400
RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffff88802c502e43 R09: 1ffff110058a05c8
R10: dffffc0000000000 R11: ffffed10058a05c9 R12: ffff88802c502e40
R13: 0000000000000021 R14: dffffc0000000000 R15: 000000001c000004
spin_unlock_irq include/linux/spinlock.h:414 [inline]
get_signal+0x11d6/0x12c0 kernel/signal.c:2903
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: 0033:0x7f5d83f7af52
Code: eb 9d 66 0f 1f 44 00 00 48 89 df 31 f6 31 c0 e8 84 9e 14 00 48 81 c4 90 00 00 00 48 98 5b c3 66 0f 1f 84 00 00 00 00 00 41 54 <55> 53 48 89 fb 48 81 ec d0 00 00 00 48 89 74 24 28 48 89 54 24 30
RSP: 002b:00007ffc6f800e70 EFLAGS: 00000206
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f5d8416e534
RDX: 0000000000010717 RSI: 0000000000000000 RDI: 00007f5d84133cfa
RBP: 00007f5d8416e534 R08: 0000000000000000 R09: 001b3438fbfbd468
R10: 000000473bd16caf R11: 00000000000064ec R12: 0000000000000000
R13: 00007f5d84340fac R14: 00007f5d84340fa0 R15: 00007f5d84340fa0
NMI backtrace for cpu 1
CPU: 1 PID: 4367 Comm: syz.1.18 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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:1818
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+0x4ad/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:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: 00 00 00 66 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 4e 2c 98 f7 48 89 df e8 86 04 99 f7 e8 11 f3 b9 f7 fb bf 01 00 00 00 06 0b 8d f7 65 8b 05 87 17 3d 76 85 c0 74 02 5b c3 e8 d4 24 3b
RSP: 0018:ffffc900034dfbc0 EFLAGS: 00000282
RAX: 75acd4977f317100 RBX: ffff88802b56a500 RCX: 75acd4977f317100
RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffff88802b56a503 R09: 1ffff110056ad4a0
R10: dffffc0000000000 R11: ffffed10056ad4a1 R12: ffff88802b56a500
R13: 0000000000000021 R14: dffffc0000000000 R15: 000000001c000004
spin_unlock_irq include/linux/spinlock.h:414 [inline]
get_signal+0x11d6/0x12c0 kernel/signal.c:2903
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: 0033:0x7f54c6a77eb9
Code: 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 01 48
RSP: 002b:00007ffd49d55c28 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f54c6a77eb9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f54c6cf2fac
RBP: 0000000000001db9 R08: 001b3438fbfbd468 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f54c6cf2fac R14: 00007f54c6cf2fa8 R15: 00007f54c6cf2fa0
sched: RT throttling activated