rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-...!: (1 GPs behind) idle=201/1/0x4000000000000000 softirq=6831/6832 fqs=8
(t=10500 jiffies g=8017 q=270)
rcu: rcu_preempt kthread starved for 10483 jiffies! g8017 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:28032 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x98/0x350 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4413 Comm: syz.1.18 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:seqcount_lockdep_reader_access+0x173/0x1c0 include/linux/seqlock.h:106
Code: 00 00 75 11 e8 5e cc 0f 00 4d 85 e4 75 16 e8 54 cc 0f 00 eb 15 e8 4d cc 0f 00 e8 88 30 41 08 4d 85 e4 74 ea e8 3e cc 0f 00 fb <48> c7 04 24 0e 36 e0 45 4b c7 04 3e 00 00 00 00 66 43 c7 44 3e 09
RSP: 0018:ffffc90000dd0d80 EFLAGS: 00000006
RAX: ffffffff8167fdfc RBX: 0000000000000000 RCX: ffff888027d1bb80
RDX: 0000000000010000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000dd0e20 R08: dffffc0000000000 R09: fffffbfff1ad32b6
R10: fffffbfff1ad32b6 R11: 1ffffffff1ad32b5 R12: 0000000000000000
R13: ffff8880b912a28c R14: 1ffff920001ba1b0 R15: dffffc0000000000
FS: 000055558832f500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 000000005f3f5000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
ktime_get+0x31/0x270 kernel/time/timekeeping.c:829
clockevents_program_event+0xe2/0x310 kernel/time/clockevents.c:326
hrtimer_interrupt+0x4de/0x8d0 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:lock_acquire+0x1f2/0x3f0 kernel/locking/lockdep.c:5627
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f6 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 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc90004c6f9c0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 198356108169de00
RDX: 0000000000000000 RSI: ffffffff8a0b2ac0 RDI: ffffffff8a59a4c0
RBP: ffffc90004c6fad8 R08: dffffc0000000000 R09: fffffbfff1ff7a1f
R10: fffffbfff1ff7a1f R11: 1ffffffff1ff7a1e R12: ffff88807a8dd528
R13: 1ffff9200098df44 R14: 0000000000000246 R15: dffffc0000000000
__might_fault+0xb3/0x110 mm/memory.c:5357
__copy_to_user include/linux/uaccess.h:143 [inline]
save_xstate_epilog arch/x86/kernel/fpu/signal.c:104 [inline]
copy_fpstate_to_sigframe+0x882/0xb90 arch/x86/kernel/fpu/signal.c:217
get_sigframe arch/x86/kernel/signal.c:295 [inline]
__setup_rt_frame arch/x86/kernel/signal.c:471 [inline]
setup_rt_frame arch/x86/kernel/signal.c:780 [inline]
handle_signal arch/x86/kernel/signal.c:824 [inline]
arch_do_signal_or_restart+0x67a/0x1300 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: 0033:0x7f538bc06ec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcb7b4a418 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007f538be5dfa8 RCX: 00007f538bc06ec9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f538be5dfac
RBP: 0000000000000000 R08: 0010351098c33dca R09: 00000006b7b4a70f
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f538be5dfac
R13: 00007f538be5dfa0 R14: 0000000000001da6 R15: 0000000000000004
NMI backtrace for cpu 0
CPU: 0 PID: 4412 Comm: syz.0.22 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 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+0x6d8/0x1110 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+0x4fe/0xc40 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: f6 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ae dc a9 f7 48 89 df e8 76 b1 aa f7 e8 11 4b cb f7 fb bf 01 00 00 00 b6 d4 9e f7 65 8b 05 97 d2 4f 76 85 c0 74 02 5b c3 e8 44 dd 4d
RSP: 0018:ffffc90004c5fcf0 EFLAGS: 00000286
RAX: ca34fb45aa782300 RBX: ffff8880596edc80 RCX: ca34fb45aa782300
RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: 0000000000000001
RBP: ffffc90004c5ff10 R08: dffffc0000000000 R09: ffffed100b2ddb91
R10: ffffed100b2ddb91 R11: 1ffff1100b2ddb90 R12: ffff888020b08000
R13: 1ffff9200098bffe R14: 1ffff9200098bfa8 R15: ffffc90004c5fff0
__ia32_sys_rt_sigreturn+0x184/0x790 arch/x86/kernel/signal.c:672
sched: RT throttling activated
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: 0033:0x7f691389df79
Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 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 04 25
RSP: 002b:00007ffe6293e100 EFLAGS: 00000206 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 00007f6913b58fa0 RCX: 00007f691389df79
RDX: 00007ffe6293e100 RSI: 00007ffe6293e230 RDI: 0000000000000021
RBP: 00007f6913984f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f6913b58fa0 R14: 00007f6913b58fa0 R15: 0000000000000004