rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10610 ticks this GP) idle=325c/1/0x4000000000000000 softirq=34338/34340 fqs=382
	(t=10500 jiffies g=52385 q=305 ncpus=2)
rcu: rcu_preempt kthread starved for 9691 jiffies! g52385 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:27456 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 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:735
CPU: 0 PID: 8902 Comm: syz.7.1288 Not tainted 6.1.138-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:29 [inline]
RIP: 0010:rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline]
RIP: 0010:rcu_is_watching+0x56/0xa0 kernel/rcu/tree.c:721
Code: f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 70 44 67 00 48 c7 c3 68 57 03 00 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 <84> c0 75 2f 8b 03 65 ff 0d 85 6c 97 7e 74 0c 83 e0 04 c1 e8 02 5b
RSP: 0018:ffffc90003877b20 EFLAGS: 00000a06
RAX: 0000000000000000 RBX: ffff8880b8e35768 RCX: f22cf0fff9ae7600
RDX: 0000000000000000 RSI: ffffffff8abf0d80 RDI: ffffffff8abf0d40
RBP: ffffc90003877c60 R08: dffffc0000000000 R09: fffffbfff1bfd046
R10: fffffbfff1bfd046 R11: 1ffffffff1bfd045 R12: 00000000fffffff2
R13: dffffc0000000000 R14: ffffffff8c3d0970 R15: dffffc0000000000
FS:  00007f06df3ff6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 0000000073ec6000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 trace_lock_release include/trace/events/lock.h:69 [inline]
 lock_release+0xd4/0x910 kernel/locking/lockdep.c:5673
 _copy_to_user+0x27/0x130 lib/usercopy.c:36
 copy_to_user include/linux/uaccess.h:169 [inline]
 copy_siginfo_to_user+0x1f/0x140 kernel/signal.c:3339
 __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+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: 0033:0x7f06df44f830
Code: 10 83 e0 01 83 e2 01 88 15 c2 5e e9 00 88 05 bf 5e e9 00 c3 50 48 8d 35 89 12 1c 00 48 8d 3d 8f 12 1c 00 31 c0 e8 30 f7 ff ff <53> 89 fb 48 83 ec 10 64 8b 04 25 94 ff ff ff 85 c0 74 2a 89 fe 31
RSP: 002b:00007f06df3fea38 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 00007f06df7b6160 RCX: 0000000000000000
RDX: 00007f06df3fea40 RSI: 00007f06df3feb70 RDI: 000000000000000b
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004ce3 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000004ce3 R15: 0000000000000000
 </TASK>