rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 0, t=10502 jiffies, g=8161, q=29 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294956101-4294945599), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g8161 f0x2 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:27840 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: 4278 Comm: syz-executor187 Not tainted 6.1.140-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:copy_user_enhanced_fast_string+0x0/0x40 arch/x86/lib/copy_user_64.S:142
Code: 8a 06 88 07 48 ff c6 48 ff c7 ff c9 75 f2 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 01 ca c3 8d 0c ca 89 ca eb 20 <0f> 01 cb 83 fa 40 72 38 89 d1 f3 a4 31 c0 0f 01 ca c3 89 ca eb 0a
RSP: 0018:ffffc90003e87cc8 EFLAGS: 00000246
RAX: ffffffff8407b401 RBX: 00000000000000c0 RCX: ffffffff8407b507
RDX: 00000000000000c0 RSI: 00007ffeb6272b68 RDI: ffffc90003e87d60
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffff520007d0fc4
R10: 0000000000000000 R11: 0000000000000010 R12: 00007fffffffef40
R13: 1ffff920007d0ffe R14: ffffc90003e87d60 R15: 00007ffeb6272b68
FS:  00005555841233c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 000000002ff63000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
 raw_copy_from_user arch/x86/include/asm/uaccess_64.h:52 [inline]
 _copy_from_user+0xf4/0x170 lib/usercopy.c:23
 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: 0033:0x7f7aa0c59f19
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:00007ffeb6272b40 EFLAGS: 00000206 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f7aa0c59f19
RDX: 00007ffeb6272b40 RSI: 00007ffeb6272c70 RDI: 0000000000000021
RBP: 0000000000000000 R08: 00007f7aa0c02990 R09: 00007f7aa0c02990
R10: 0000000000000000 R11: 0000000000000206 R12: 00007f7aa0ca033c
R13: 00007f7aa0c9a106 R14: 00007ffeb6273100 R15: 0000000000000000
 </TASK>