rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-...!: (10499 ticks this GP) idle=f8f/1/0x4000000000000000 softirq=6940/6940 fqs=51
(t=10500 jiffies g=8441 q=1131)
rcu: rcu_preempt kthread starved for 10382 jiffies! g8441 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:27440 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 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/0x11f0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9a/0x370 kernel/rcu/tree.c:2145
kthread+0x42e/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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4394 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline]
RIP: 0010:static_key_false include/linux/jump_label.h:212 [inline]
RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:156 [inline]
RIP: 0010:wrmsr arch/x86/include/asm/msr.h:263 [inline]
RIP: 0010:native_apic_msr_write+0x35/0x50 arch/x86/include/asm/apic.h:208
Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 89 f6 31 d2 e9 9f 8c d4 02 66 2e 0f 1f 84 00 00 00 00 00
RSP: 0018:ffffc90000dd0e70 EFLAGS: 00000046
RAX: 000000000007f93e RBX: 000000000007f93e RCX: 0000000000000838
RDX: 0000000000000000 RSI: 000000000007f93e RDI: 0000000000000838
RBP: 0000000000000000 R08: ffffffff8d8aeaef R09: 1ffffffff1b15d5d
R10: dffffc0000000000 R11: fffffbfff1b15d5e R12: dffffc0000000000
R13: 00000000100062fc R14: ffffffff8be3a9d8 R15: dffffc0000000000
FS: 000055556a4ad500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 0000000024b72000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
apic_write arch/x86/include/asm/apic.h:395 [inline]
lapic_next_event+0x5b/0x70 arch/x86/kernel/apic/apic.c:468
clockevents_program_event+0x1bc/0x310 kernel/time/clockevents.c:334
hrtimer_interrupt+0x4cb/0x8b0 kernel/time/hrtimer.c:1824
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 6e cf 94 f7 48 89 df e8 a6 a6 95 f7 e8 91 8f b6 f7 fb bf 01 00 00 00 66 bf 89 f7 65 8b 05 77 e6 39 76 85 c0 74 02 5b c3 e8 b4 f3 37
RSP: 0018:ffffc9000353fbc0 EFLAGS: 00000282
RAX: 9eba0371f4ce3500 RBX: ffff88802aafae40 RCX: 9eba0371f4ce3500
RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffff88802aafae43 R09: 1ffff1100555f5c8
R10: dffffc0000000000 R11: ffffed100555f5c9 R12: dffffc0000000000
R13: ffff88802aafae40 R14: 0000000000000021 R15: 000000001c000004
spin_unlock_irq include/linux/spinlock.h:414 [inline]
get_signal+0x11f2/0x12e0 kernel/signal.c:2904
arch_do_signal_or_restart+0xe6/0x12a0 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: 0033:0x7fe8b08b8090
Code: 00 00 45 31 d2 48 83 b8 88 00 00 00 ff 41 b9 03 00 00 00 ba 01 00 00 00 0f 85 59 ff ff ff eb ca 66 2e 0f 1f 84 00 00 00 00 00 <80> 3d 4e e6 ee 00 00 74 40 80 3d 33 e6 ee 00 00 74 2e 80 3d 36 e6
RSP: 002b:00007ffcf1879c88 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007ffcf1879d70 RCX: 00007fe8b09eee99
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 000000000003ec8b R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b31b20000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe8b0c76fac R14: 00007fe8b0c76fa8 R15: 00007fe8b0c76fa0
NMI backtrace for cpu 0
sched: RT throttling activated
CPU: 0 PID: 4393 Comm: syz.1.18 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+0x22d/0x380 kernel/rcu/tree_stall.h:349
print_cpu_stall+0x31f/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+0x6ec/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+0x4b0/0xb60 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x397/0x8b0 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:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04
RSP: 0018:ffffc9000354fb40 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: f467ce707901bb00
RDX: 0000000000000000 RSI: ffffffff8a2b3e80 RDI: ffffffff8a7a2a40
RBP: ffffc9000354fc60 R08: dffffc0000000000 R09: 1ffffffff203d21e
R10: dffffc0000000000 R11: fffffbfff203d21f R12: ffff88807e317828
R13: 1ffff920006a9f74 R14: 0000000000000246 R15: dffffc0000000000
__might_fault+0xb3/0x110 mm/memory.c:5357
_copy_from_user+0x29/0x170 lib/usercopy.c:14
copy_from_user include/linux/uaccess.h:192 [inline]
restore_sigcontext arch/x86/kernel/signal.c:91 [inline]
__ia32_sys_rt_sigreturn+0x21c/0x750 arch/x86/kernel/signal.c:674
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f4401cf3219
Code: 11 06 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 0c 25
RSP: 002b:00007ffc427da5c0 EFLAGS: 00000202 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4401cf3219
RDX: 00007ffc427da5c0 RSI: 00007ffc427da6f0 RDI: 0000000000000021
RBP: 0000000000001e90 R08: 0021a0e45e16e08e R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007f4401fd9fac R14: 00007f4401fd9fa8 R15: 00007f4401fd9fa0