rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 1, t=10502 jiffies, g=6837, q=51 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294953994-4294943494), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10500 jiffies! g6837 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:27344 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x14d2/0x44d0 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
 </TASK>
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: 5806 Comm: syz-executor223 Not tainted 6.6.101-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:lock_release+0x0/0x8b0 kernel/locking/lockdep.c:5762
Code: 03 38 c1 0f 8c 1b fa ff ff 48 89 df e8 99 51 75 00 e9 0e fa ff ff bb 2f 00 00 00 e9 24 fa ff ff 66 2e 0f 1f 84 00 00 00 00 00 <f3> 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48
RSP: 0018:ffffc90000007c28 EFLAGS: 00000083
RAX: 0000000000000001 RBX: ffff888018306318 RCX: ffff888018305a00
RDX: 0000000000010000 RSI: ffffffff815388c9 RDI: ffffffff8cd2fba0
RBP: 0000000000000001 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f64 R12: ffff888078ceb780
R13: ffffffff815388c9 R14: ffff888078ceb780 R15: 1ffff11003060c63
FS:  0000555574d503c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 000000002ebfe000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 rcu_lock_release include/linux/rcupdate.h:344 [inline]
 rcu_read_unlock include/linux/rcupdate.h:819 [inline]
 __lock_task_sighand+0x2b4/0x2d0 kernel/signal.c:1429
 lock_task_sighand include/linux/sched/signal.h:742 [inline]
 send_sigqueue+0x239/0x710 kernel/signal.c:2009
 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
 </IRQ>
 <TASK>
 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 c8 f0 f6 48 89 df e8 b2 9a f1 f6 e8 4d 37 15 f7 fb bf 01 00 00 00 <e8> 92 b2 e4 f6 65 8b 05 93 f8 8c 75 85 c0 74 02 5b c3 e8 70 da 89
RSP: 0018:ffffc900046afc98 EFLAGS: 00000282
RAX: e28bc58ea1255d00 RBX: ffff888078ceb780 RCX: e28bc58ea1255d00
RDX: dffffc0000000000 RSI: ffffffff8aaaba40 RDI: 0000000000000001
RBP: ffff888078cebc18 R08: ffffffff8e4a84ef R09: 1ffffffff1c9509d
R10: dffffc0000000000 R11: fffffbfff1c9509e R12: 1ffff1100f19d783
R13: 0000000000000021 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: 0033:0x7ff15f821899
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 19 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe7dc7d3f8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007ff15f821899
RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 00007ff15f7e1990 R09: 00007ff15f7e1990
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff15f87f33c
R13: 00007ff15f879106 R14: 00007ffe7dc7d430 R15: 0000000000000000
 </TASK>