rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=7665, q=63 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294955337-4294944835), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g7665 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:27840 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 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
 </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: 4278 Comm: syz-executor235 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline]
RIP: 0010:lock_release+0x543/0x910 kernel/locking/lockdep.c:5684
Code: 00 00 00 00 00 fc ff df 4d 85 e4 0f 85 ff fc ff ff 48 8b 7c 24 08 48 8b 74 24 10 48 8b 54 24 30 e8 32 6b 00 00 4c 8b 7c 24 18 <48> c7 c7 80 16 8c 8a e8 a1 2f b4 08 b8 ff ff ff ff 65 0f c1 05 a4
RSP: 0018:ffffc90000007b20 EFLAGS: 00000046
RAX: 1ffff1100f2ba15a RBX: b1848fc2b17dd0f4 RCX: 0000000000000001
RDX: 0000000000000001 RSI: ffffffff8cb2abe0 RDI: ffff8880795d0b08
RBP: ffffc90000007c40 R08: dffffc0000000000 R09: fffffbfff1c3ecb6
R10: fffffbfff1c3ecb6 R11: 1ffffffff1c3ecb5 R12: ffff8880795d0b08
R13: dffffc0000000000 R14: ffff8880795d0ad0 R15: 1ffff92000000f70
FS:  00007fa4e7e296c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 0000000026aa4000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_lock_release include/linux/rcupdate.h:355 [inline]
 rcu_read_unlock include/linux/rcupdate.h:824 [inline]
 send_sigqueue+0x492/0x600 kernel/signal.c:2010
 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: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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:stac arch/x86/include/asm/uaccess_64.h:96 [inline]
RIP: 0010:__clear_user arch/x86/include/asm/uaccess_64.h:97 [inline]
RIP: 0010:clear_user arch/x86/include/asm/uaccess_64.h:124 [inline]
RIP: 0010:copy_siginfo_to_user+0xcd/0x140 kernel/signal.c:3341
Code: 2f 00 48 b8 b1 ef ff ff ff 7f 00 00 48 39 c3 73 49 e8 c7 a8 2f 00 48 c7 c7 a0 2e 8b 8a be 60 00 00 00 e8 76 4a 6d 00 0f 01 cb <45> 31 f6 b9 50 00 00 00 31 c0 48 89 df e8 a1 0a ba 08 48 89 cb 0f
RSP: 0018:ffffc90003d47ca0 EFLAGS: 00040246
RAX: 01192d03e5724500 RBX: 00007fa4e7e28d20 RCX: 01192d03e5724500
RDX: 0000000000000000 RSI: ffffffff8a8c1680 RDI: ffffffff8adefd20
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1c3ecb6
R10: fffffbfff1c3ecb6 R11: 1ffffffff1c3ecb5 R12: 00000000fffffff2
R13: 1ffff920007a8fff R14: 0000000000000000 R15: ffffc90003d47fc8
 __setup_rt_frame arch/x86/kernel/signal.c:491 [inline]
 setup_rt_frame arch/x86/kernel/signal.c:784 [inline]
 handle_signal arch/x86/kernel/signal.c:828 [inline]
 arch_do_signal_or_restart+0xd2e/0x1230 arch/x86/kernel/signal.c:873
 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: 0033:0x7fa4e7e70fc7
Code: 14 25 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 1c 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
RSP: 002b:00007fa4e7e29178 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007fa4e7ef3308 RCX: 00007fa4e7e70fc9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fa4e7ef3308
RBP: 00007fa4e7ef3300 R08: 00007fa4e7e296c0 R09: 00007fa4e7e296c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa4e7ef330c
R13: 0000000000000000 R14: 00007ffc38e72650 R15: 00007ffc38e72738
 </TASK>