rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=fd64/1/0x4000000000000000 softirq=48503/48504 fqs=1 (t=10502 jiffies g=66433 q=17 ncpus=2) rcu: rcu_preempt kthread starved for 10501 jiffies! g66433 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:26912 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 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 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:741 CPU: 0 PID: 13075 Comm: syz.2.1973 Not tainted 6.1.147-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:lock_is_held_type+0x13a/0x190 kernel/locking/lockdep.c:5710 Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc90003537918 EFLAGS: 00000206 RAX: 1fabacae6cac5900 RBX: ffff888073ff0000 RCX: 1fabacae6cac5900 RDX: 0000000000000000 RSI: ffffffff8a8c15e0 RDI: ffffffff8adef320 RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffc90003537b90 R10: fffff520006a6f76 R11: 1ffff920006a6f72 R12: dffffc0000000000 R13: 0000000000000246 R14: ffffffff8cb2aee0 R15: 00000000ffffffff FS: 00007ff4be0696c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f618ff8 CR3: 0000000045862000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:283 [inline] __might_resched+0xf2/0x610 kernel/sched/core.c:9928 __might_fault+0x6d/0x120 mm/memory.c:5850 __copy_to_user include/linux/uaccess.h:111 [inline] save_xstate_epilog arch/x86/kernel/fpu/signal.c:127 [inline] copy_fpstate_to_sigframe+0xa53/0xcb0 arch/x86/kernel/fpu/signal.c:245 get_sigframe arch/x86/kernel/signal.c:297 [inline] __setup_rt_frame arch/x86/kernel/signal.c:472 [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+0x610/0x1230 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: 0033:0x7ff4bd18ebe7 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:00007ff4be0690e8 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007ff4bd3b6098 RCX: 00007ff4bd18ebe9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007ff4bd3b6098 RBP: 00007ff4bd3b6090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff4bd3b6128 R14: 00007ffdf7825480 R15: 00007ffdf7825568