syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 0, t=10502 jiffies, g=7165, q=37 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294955329-4294944826), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10504 jiffies! g7165 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:26712 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6561
 schedule+0xbf/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 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:
CPU: 0 PID: 4273 Comm: syz-executor138 Not tainted 6.1.134-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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: d1 83 f5 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 5e aa ae f6 48 89 df e8 c6 e8 af f6 e8 81 3a d5 f6 fb bf 01 00 00 00 <e8> d6 68 a2 f6 65 8b 05 97 3e 46 75 85 c0 74 02 5b c3 e8 34 62 44
RSP: 0018:ffffc90003db7b30 EFLAGS: 00000286
RAX: 60dbe5bfce2ee400 RBX: ffff88802f4eef00 RCX: ffffffff973c3103
RDX: dffffc0000000000 RSI: ffffffff8b0c1ec0 RDI: 0000000000000001
RBP: ffffc90003db7c70 R08: dffffc0000000000 R09: ffffed1005e9dde1
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff11005e9de73
R13: 000000001c000004 R14: 0000000000000021 R15: ffff88802f4ef398
FS:  0000555581f423c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 000000007ba33000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 get_signal+0x151f/0x17a0 kernel/signal.c:2874
 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x6a/0x100 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+0x60/0x270 kernel/entry/common.c:303
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc334b2c899
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:00007ffc8d2689a8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007fc334b2c899
RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 00007fc334aec990 R09: 00007fc334aec990
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc334b8a33c
R13: 00007fc334b84106 R14: 00007ffc8d2689e0 R15: 0000000000000000
 </TASK>