rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10499 ticks this GP) idle=cdfc/1/0x4000000000000000 softirq=9626/9626 fqs=6
	(t=10500 jiffies g=10061 q=80 ncpus=2)
rcu: rcu_preempt kthread starved for 10488 jiffies! g10061 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:26912 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10e9/0x40d0 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4430 Comm: syz.0.26 Not tainted 6.1.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:228 [inline]
RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:240 [inline]
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline]
RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:444 [inline]
RIP: 0010:cpu_online include/linux/cpumask.h:1030 [inline]
RIP: 0010:trace_hrtimer_expire_exit include/trace/events/timer.h:286 [inline]
RIP: 0010:__run_hrtimer kernel/time/hrtimer.c:1755 [inline]
RIP: 0010:__hrtimer_run_queues+0x5e2/0xd60 kernel/time/hrtimer.c:1816
Code: 00 00 e8 91 e7 0f 00 45 89 fd 41 c1 ef 06 4a 8d 3c fd a8 85 fe 8d be 08 00 00 00 e8 c8 61 61 00 31 f6 4c 0f a3 2d a6 96 8d 0c <41> 0f 92 c7 40 0f 92 c6 bf 02 00 00 00 e8 bc e9 0f 00 45 84 ff 74
RSP: 0018:ffffc900001e0d20 EFLAGS: 00000047
RAX: ffffffff8170ee01 RBX: ffff8880b8f2a648 RCX: ffffffff8170eef8
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8dfe85a8
RBP: ffffc900001e0e88 R08: dffffc0000000000 R09: fffffbfff1bfd0b6
R10: fffffbfff1bfd0b6 R11: 1ffffffff1bfd0b5 R12: ffff88807f7360b0
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f1d56cc46c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 000000005cc11000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1878
 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:__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 de d0 49 f7 48 89 df e8 36 96 4a f7 e8 31 97 6d f7 fb bf 01 00 00 00 <e8> 46 13 3e f7 65 8b 05 17 d4 e8 75 85 c0 74 02 5b c3 e8 64 e5 e6
RSP: 0018:ffffc9000488fbb8 EFLAGS: 00000286
RAX: 2c044bb27aeb5900 RBX: ffff888056e83780 RCX: 2c044bb27aeb5900
RDX: dffffc0000000000 RSI: ffffffff8a6bffe0 RDI: 0000000000000001
RBP: ffff888056e83c18 R08: dffffc0000000000 R09: ffffed100add06f1
R10: ffffed100add06f1 R11: 1ffff1100add06f0 R12: 1ffff1100add0783
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+0xb1/0x140 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: 0033:0x7f1d55d8e927
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:00007f1d56cc4038 EFLAGS: 00000246
RAX: 0000000000000113 RBX: 00007f1d55fb5fa0 RCX: 00007f1d55d8e929
RDX: 0000000000000007 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 00007f1d55e10b39 R08: 0000000008000f28 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f1d55fb5fa0 R15: 00007fffa8184098
 </TASK>
CPU: 0 PID: 4435 Comm: syz.3.27 Not tainted 6.1.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:lock_acquire+0x20f/0x490 kernel/locking/lockdep.c:5666
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc900048bfb60 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 7c8c9579aefd0300
RDX: 0000000000000000 RSI: ffffffff8a6c1160 RDI: ffffffff8abf1360
RBP: ffffc900048bfc80 R08: dffffc0000000000 R09: fffffbfff211704f
R10: fffffbfff211704f R11: 1ffffffff211704e R12: 0000000000000000
R13: 1ffff92000917f78 R14: 0000000000000246 R15: dffffc0000000000
FS:  00007f88cee9a6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2fcdc3 CR3: 0000000054d7a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __might_fault+0xc2/0x120 mm/memory.c:5852
 _copy_from_user+0x27/0x170 lib/usercopy.c:14
 copy_from_user include/linux/uaccess.h:161 [inline]
 restore_sigcontext arch/x86/kernel/signal.c:92 [inline]
 __ia32_sys_rt_sigreturn+0x1e6/0x790 arch/x86/kernel/signal.c:675
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f88cdf2ab19
Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25
RSP: 002b:00007f88cee99b40 EFLAGS: 00000206 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 00007f88ce1b5fa8 RCX: 00007f88cdf2ab19
RDX: 00007f88cee99b40 RSI: 00007f88cee99c70 RDI: 0000000000000021
RBP: 00007f88ce1b5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 00007f88ce1b5fac
R13: 0000000000000000 R14: 00007ffecc979a90 R15: 00007ffecc979b78
 </TASK>