rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 1-...!: (10499 ticks this GP) idle=34f/1/0x4000000000000000 softirq=14734/14741 fqs=49
(t=10501 jiffies g=17301 q=1056)
rcu: rcu_preempt kthread starved for 10398 jiffies! g17301 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:27904 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6053 Comm: syz.4.359 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__lock_acquire+0x1339/0x7c60 kernel/locking/lockdep.c:5009
Code: fc ff df 42 0f b6 04 00 84 c0 0f 85 e3 5a 00 00 83 3d 3a 3d b0 14 00 0f 84 e0 04 00 00 31 db 48 83 c3 40 48 89 d8 48 c1 e8 03 <42> 80 3c 00 00 74 12 48 89 df e8 c8 21 60 00 49 b8 00 00 00 00 00
RSP: 0018:ffffc90000007860 EFLAGS: 00000806
RAX: 1ffffffff1f28df0 RBX: ffffffff8f946f80 RCX: ffffffff815c11f9
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ffbe0c0
RBP: ffffc90000007ab0 R08: dffffc0000000000 R09: fffffbfff1ff7c19
R10: fffffbfff1ff7c19 R11: 1ffffffff1ff7c18 R12: 000000005daa2f23
R13: ffff888025e39dc0 R14: 00000000609d057e R15: ffff888025e3a920
FS: 00007feee94716c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 000000005f586000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
rcu_read_lock include/linux/rcupdate.h:740 [inline]
__lock_task_sighand+0x21/0x290 kernel/signal.c:1387
lock_task_sighand include/linux/sched/signal.h:710 [inline]
send_sigqueue+0x177/0x620 kernel/signal.c:1975
posix_timer_event kernel/time/posix-timers.c:360 [inline]
posix_timer_fn+0x16a/0x3d0 kernel/time/posix-timers.c:386
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x53d/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 de 9e a9 f7 48 89 df e8 a6 73 aa f7 e8 41 0d cb f7 fb bf 01 00 00 00 76 95 9e f7 65 8b 05 07 93 4f 76 85 c0 74 02 5b c3 e8 b4 9d 4d
RSP: 0018:ffffc9000352fbc0 EFLAGS: 00000282
RAX: 49a70a0104455000 RBX: ffff888062669bc0 RCX: 49a70a0104455000
RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: 0000000000000001
RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed100c4cd379
R10: ffffed100c4cd379 R11: 1ffff1100c4cd378 R12: ffff888062669bc0
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+0xc1/0x1300 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: 0033:0x7feeeb20a6c7
Code: ff ff 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
RSP: 002b:00007feee94710e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007feeeb460fa8 RCX: 00007feeeb20a6c9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007feeeb460fa8
RBP: 00007feeeb460fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007feeeb461038 R14: 00007ffec3af97e0 R15: 00007ffec3af98c8
NMI backtrace for cpu 1
CPU: 1 PID: 6027 Comm: syz.3.355 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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 de 9e a9 f7 48 89 df e8 a6 73 aa f7 e8 41 0d cb f7 fb bf 01 00 00 00 76 95 9e f7 65 8b 05 07 93 4f 76 85 c0 74 02 5b c3 e8 b4 9d 4d
RSP: 0018:ffffc90003607bc0 EFLAGS: 00000282
RAX: 4c3e9cc4fcaa4a00 RBX: ffff88802a8c2500 RCX: 4c3e9cc4fcaa4a00
RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: 0000000000000001
RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed10055184a1
R10: ffffed10055184a1 R11: 1ffff110055184a0 R12: ffff88802a8c2500
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+0xc1/0x1300 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: 0033:0x7f7456d156c9
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:00007ffe0fba8a88 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 000000000003c8a6 RCX: 00007f7456d156c9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f7456f6bfac
RBP: 0000000000000fd2 R08: 0002571a6266a8d0 R09: 0000000b0fba8d7f
R10: 00007ffe0fba8b80 R11: 0000000000000246 R12: 00007f7456f6bfac
R13: 00007ffe0fba8b80 R14: 000000000003d878 R15: 00007ffe0fba8ba0