rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10523 ticks this GP) idle=e7c4/1/0x4000000000000000 softirq=68137/68140 fqs=507 (t=10500 jiffies g=97097 q=216 ncpus=2) rcu: rcu_preempt kthread starved for 9482 jiffies! g97097 f0x0 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:27200 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 0 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:735 CPU: 1 PID: 14755 Comm: syz.4.2646 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:ffffc9000359fb50 EFLAGS: 00000282 RAX: b34832b957276900 RBX: ffff88807d8bef00 RCX: b34832b957276900 RDX: dffffc0000000000 RSI: ffffffff8a6bfe00 RDI: 0000000000000001 RBP: ffffc9000359fcb0 R08: dffffc0000000000 R09: ffffed100fb17de1 R10: ffffed100fb17de1 R11: 1ffff1100fb17de0 R12: dffffc0000000000 R13: 0000000000010000 R14: 0000000000000000 R15: 0000000000000010 FS: 00007f41f6c6c6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000080 CR3: 0000000065786000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: set_current_blocked kernel/signal.c:3044 [inline] signal_delivered kernel/signal.c:2907 [inline] signal_setup_done+0x28c/0x440 kernel/signal.c:2919 handle_signal arch/x86/kernel/signal.c:846 [inline] arch_do_signal_or_restart+0xeba/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: 0033:0x7f41f5c4d980 Code: 44 24 20 0f 29 44 24 30 0f 29 44 24 40 48 8b 44 24 08 ff d0 48 83 c4 50 31 c0 5b 5d 41 5c 41 5d 41 5e c3 0f 1f 80 00 00 00 00 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 c3 66 66 2e 0f 1f RSP: 002b:00007f41f6c6bb38 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 00007f41f5fb5fa8 RCX: 00007f41f5d8e969 RDX: 00007f41f6c6bb40 RSI: 00007f41f6c6bc70 RDI: 0000000000000011 RBP: 00007f41f5fb5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f41f5fb5fac R13: 0000000000000000 R14: 00007ffdcb8b7850 R15: 00007ffdcb8b7938