rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-...!: (10499 ticks this GP) idle=c914/1/0x4000000000000000 softirq=9095/9096 fqs=9
(t=10501 jiffies g=9541 q=239 ncpus=2)
rcu: rcu_preempt kthread starved for 10484 jiffies! g9541 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:27840 pid:16 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965
rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
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: 4477 Comm: syz.0.27 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline]
RIP: 0010:mark_lock+0x9c/0x320 kernel/locking/lockdep.c:4606
Code: 89 c7 41 81 e7 ff 1f 00 00 c1 e8 03 25 f8 03 00 00 48 8d b8 40 22 ae 90 be 08 00 00 00 e8 dc 46 6d 00 4c 0f a3 3d 54 77 4a 0f <73> 10 4b 8d 04 7f c1 e0 06 4c 8d b8 00 a1 46 90 eb 24 48 c7 c0 40
RSP: 0018:ffffc900001e0840 EFLAGS: 00000057
RAX: 0000000000000101 RBX: ffff888027e28000 RCX: ffffffff8163aae4
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90ae2340
RBP: 0000000000000008 R08: dffffc0000000000 R09: fffffbfff215c469
R10: fffffbfff215c469 R11: 1ffffffff215c468 R12: 0000000000000100
R13: dffffc0000000000 R14: ffff888027e28ae0 R15: 000000000000082b
FS: 00007fd7fb7af6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 00000000553dd000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
mark_usage kernel/locking/lockdep.c:4549 [inline]
__lock_acquire+0xd6f/0x7c50 kernel/locking/lockdep.c:5003
lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
posix_timer_fn+0x32/0x3d0 kernel/time/posix-timers.c:380
__run_hrtimer kernel/time/hrtimer.c:1747 [inline]
__hrtimer_run_queues+0x554/0xd60 kernel/time/hrtimer.c:1811
hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1873
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
__sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: f5 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ee f7 41 f7 48 89 df e8 46 bd 42 f7 e8 71 af 65 f7 fb bf 01 00 00 00 96 3a 36 f7 65 8b 05 97 f3 e0 75 85 c0 74 02 5b c3 e8 e4 04 df
RSP: 0018:ffffc9000489fbb8 EFLAGS: 00000286
RAX: 73b3f96aa4491b00 RBX: ffff88805456ef00 RCX: 73b3f96aa4491b00
RDX: dffffc0000000000 RSI: ffffffff8a8c0500 RDI: 0000000000000001
RBP: ffff88805456f398 R08: dffffc0000000000 R09: ffffed100a8adde1
R10: ffffed100a8adde1 R11: 1ffff1100a8adde0 R12: 1ffff1100a8ade73
R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000
spin_unlock_irq include/linux/spinlock.h:401 [inline]
get_signal+0x1163/0x1350 kernel/signal.c:2874
arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd7fa98eec7
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:00007fd7fb7af0e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007fd7fabe5fa8 RCX: 00007fd7fa98eec9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fd7fabe5fa8
RBP: 00007fd7fabe5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd7fabe6038 R14: 00007ffd9e44e620 R15: 00007ffd9e44e708
CPU: 0 PID: 4466 Comm: syz.4.24 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: f5 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ee f7 41 f7 48 89 df e8 46 bd 42 f7 e8 71 af 65 f7 fb bf 01 00 00 00 96 3a 36 f7 65 8b 05 97 f3 e0 75 85 c0 74 02 5b c3 e8 e4 04 df
RSP: 0018:ffffc900049bfbb8 EFLAGS: 00000286
RAX: f77b16da7b8cc800 RBX: ffff888054569280 RCX: f77b16da7b8cc800
RDX: dffffc0000000000 RSI: ffffffff8a8c0500 RDI: 0000000000000001
RBP: ffff888054569718 R08: dffffc0000000000 R09: ffffed100a8ad251
R10: ffffed100a8ad251 R11: 1ffff1100a8ad250 R12: 1ffff1100a8ad2e3
R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000
FS: 00007f3f375ff6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2eeab1c81c CR3: 000000001e313000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
spin_unlock_irq include/linux/spinlock.h:401 [inline]
get_signal+0x1163/0x1350 kernel/signal.c:2874
arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f3f3678eec7
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:00007f3f375ff0e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f3f369e5fa8 RCX: 00007f3f3678eec9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f3f369e5fa8
RBP: 00007f3f369e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3f369e6038 R14: 00007ffe96ff71a0 R15: 00007ffe96ff7288
sched: RT throttling activated