rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 1, t=10502 jiffies, g=8877, q=593 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10493 (4294955770-4294945277), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10494 jiffies! g8877 f0x2 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:26568 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x14e2/0x4580 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
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: 5948 Comm: syz.2.18 Not tainted 6.6.94-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:check_preemption_disabled+0x49/0x110 lib/smp_processor_id.c:55
Code: 65 8b 0d 62 6d 9d 75 f7 c1 ff ff ff 7f 74 1f 65 48 8b 0c 25 28 00 00 00 48 3b 4c 24 08 0f 85 c4 00 00 00 48 83 c4 10 5b 41 5e <41> 5f 5d c3 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00
RSP: 0018:ffffc90000007c00 EFLAGS: 00000086
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 5096a88e6ede0300
RDX: ffff88807e3c8000 RSI: ffffffff8afc68e0 RDI: ffffffff8afc68a0
RBP: 0000000000000001 R08: ffffffff8e49ab2f R09: 1ffffffff1c93565
R10: dffffc0000000000 R11: fffffbfff1c93566 R12: 0000000000000011
R13: ffff88807e3c8000 R14: 0000000000000000 R15: ffff888062bf1f68
FS: 000055557f324500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2bc5ffff CR3: 0000000076c20000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline]
rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:700
trace_signal_generate+0x81/0x1d0 include/trace/events/signal.h:50
send_sigqueue+0x4b3/0x710 kernel/signal.c:2037
posix_timer_event kernel/time/posix-timers.c:299 [inline]
posix_timer_fn+0x16e/0x3d0 kernel/time/posix-timers.c:325
__run_hrtimer kernel/time/hrtimer.c:1755 [inline]
__hrtimer_run_queues+0x51e/0xc40 kernel/time/hrtimer.c:1819
hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1881
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
__sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202
Code: 00 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 9a a7 f7 f6 48 89 df e8 b2 79 f8 f6 e8 cd 25 1c f7 fb bf 01 00 00 00 f2 90 eb f6 65 8b 05 03 e7 93 75 85 c0 74 02 5b c3 e8 e0 c8 90
RSP: 0018:ffffc90003397c98 EFLAGS: 00000282
RAX: 5096a88e6ede0300 RBX: ffff88805f2f3780 RCX: 5096a88e6ede0300
RDX: dffffc0000000000 RSI: ffffffff8aaab2c0 RDI: 0000000000000001
RBP: ffff88805f2f3a18 R08: ffffffff8e49ab2f R09: 1ffffffff1c93565
R10: dffffc0000000000 R11: fffffbfff1c93566 R12: 1ffff1100be5e743
R13: 0000000000000011 R14: dffffc0000000000 R15: 0000000000000000
spin_unlock_irq include/linux/spinlock.h:401 [inline]
get_signal+0x11f5/0x1400 kernel/signal.c:2905
arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fe09698e929
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:00007fffea049ad8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007fe096bb5fa0 RCX: 00007fe09698e929
RDX: 0000200000000240 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fe096a10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe096bb5fa0 R14: 00007fe096bb5fa0 R15: 0000000000000004