rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
(detected by 0, t=10502 jiffies, g=8817, q=81 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294960490-4294949988), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g8817 f0x2 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:27848 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:2167
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: 4532 Comm: syz.2.19 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline]
RIP: 0010:__lock_acquire+0x12d4/0x7c50 kernel/locking/lockdep.c:5046
Code: 00 48 8b 44 24 50 42 0f b6 04 00 84 c0 0f 85 39 5a 00 00 48 8b 44 24 18 8b 00 89 c3 81 e3 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 9b f6 6d 00 48 0f a3 1d e3
RSP: 0018:ffffc900001e0860 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81630e22
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90ae2248
RBP: ffffc900001e0ab0 R08: dffffc0000000000 R09: fffffbfff215c44a
R10: fffffbfff215c44a R11: 1ffffffff215c449 R12: 000000002e4489ed
R13: 00000000dd311f9c R14: 00000000b596d9f6 R15: ffff88807fcec650
FS: 00005555649e4500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f363fff CR3: 000000002a04f000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
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
debug_object_deactivate+0x63/0x340 lib/debugobjects.c:753
debug_hrtimer_deactivate kernel/time/hrtimer.c:453 [inline]
debug_deactivate+0x29/0x240 kernel/time/hrtimer.c:509
__run_hrtimer kernel/time/hrtimer.c:1715 [inline]
__hrtimer_run_queues+0x2df/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 8e 8f 41 f7 48 89 df e8 e6 54 42 f7 e8 31 48 65 f7 fb bf 01 00 00 00 76 cd 35 f7 65 8b 05 f7 84 e0 75 85 c0 74 02 5b c3 e8 44 96 de
RSP: 0018:ffffc900035c7b98 EFLAGS: 00000282
RAX: 16f7405f6f49a100 RBX: ffff88805a8dd340 RCX: 16f7405f6f49a100
RDX: dffffc0000000000 RSI: ffffffff8a8c0580 RDI: 0000000000000001
RBP: ffff88805a8dd5d8 R08: dffffc0000000000 R09: ffffed100b51ba69
R10: ffffed100b51ba69 R11: 1ffff1100b51ba68 R12: 1ffff1100b51babb
R13: 0000000000000011 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+0xb7/0x1240 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: 0033:0x7fdc3898f749
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:00007ffdeeab3e18 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007fdc38be5fa0 RCX: 00007fdc3898f749
RDX: 0000200000000300 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fdc38a13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdc38be5fa0 R14: 00007fdc38be5fa0 R15: 0000000000000004