rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=20249, q=147 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294968048-4294957546), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g20249 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:27040 pid:16 ppid:2 flags:0x00004000 Call Trace: 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 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 5677 Comm: syz.3.288 Not tainted 6.1.138-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 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: f5 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 4e 1b 4a f7 48 89 df e8 a6 e0 4a f7 e8 11 e3 6d f7 fb bf 01 00 00 00 b6 5d 3e f7 65 8b 05 b7 22 e9 75 85 c0 74 02 5b c3 e8 04 34 e7 RSP: 0018:ffffc9001004fbb8 EFLAGS: 00000286 RAX: 6701b88c59aff100 RBX: ffff88807d21c0c0 RCX: 6701b88c59aff100 RDX: dffffc0000000000 RSI: ffffffff8a6bfe00 RDI: 0000000000000001 RBP: ffff88807d21c558 R08: dffffc0000000000 R09: ffffed100fa43819 R10: ffffed100fa43819 R11: 1ffff1100fa43818 R12: 1ffff1100fa438ab R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000 FS: 00007f14096426c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d80eff8 CR3: 000000005726a000 CR4: 00000000003506f0 DR0: 0000000000001857 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: 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: 0033:0x7f140878e967 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:00007f1409642038 EFLAGS: 00000246 RAX: 0000000000000113 RBX: 00007f14089b5fa0 RCX: 00007f140878e969 RDX: 0000000000000006 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007f1408810ab1 R08: 0000000008000f28 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f14089b5fa0 R15: 00007ffdcd45c958