rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=089c/1/0x4000000000000000 softirq=19056/19057 fqs=192 rcu: (t=10502 jiffies g=13221 q=1074 ncpus=2) rcu: rcu_preempt kthread starved for 10068 jiffies! g13221 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:27224 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 53 e8 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d b3 e9 0d 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000a087b8 EFLAGS: 00000246 RAX: ffffffff8172213d RBX: 0000000000000003 RCX: ffff88801ceada00 RDX: 0000000000000100 RSI: ffffffff8d9ba295 RDI: ffffffff8be33f00 RBP: ffffc90000a08890 R08: ffffffff8fa3a637 R09: 1ffffffff1f474c6 R10: dffffc0000000000 R11: fffffbfff1f474c7 R12: dffffc0000000000 R13: 0000000000000200 R14: 0000000000000003 R15: 1ffff920001410fc FS: 0000000000000000(0000) GS:ffff888125d13000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a8e9cb8a38 CR3: 0000000072fa0000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] kvm_wait+0x232/0x290 arch/x86/kernel/kvm.c:1064 pv_wait arch/x86/include/asm/paravirt.h:569 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:466 [inline] __pv_queued_spin_lock_slowpath+0x7bf/0xb60 kernel/locking/qspinlock.c:325 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:557 [inline] queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x21f/0x290 kernel/locking/spinlock_debug.c:116 spin_lock include/linux/spinlock.h:351 [inline] __xfrm_state_delete+0xba/0xca0 net/xfrm/xfrm_state.c:818 xfrm_timer_handler+0x18f/0xa00 net/xfrm/xfrm_state.c:716 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x529/0xc60 kernel/time/hrtimer.c:1825 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1842 handle_softirqs+0x283/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 53 e8 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d b3 e9 0d 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197de0 EFLAGS: 000002c2 RAX: 1ba04ec562444300 RBX: ffffffff819683f8 RCX: 1ba04ec562444300 RDX: 0000000000000001 RSI: ffffffff8d9ba295 RDI: ffffffff8be33f00 RBP: ffffc90000197f20 R08: ffff8880b8732f9b R09: 1ffff110170e65f3 R10: dffffc0000000000 R11: ffffed10170e65f4 R12: ffffffff8fa3a630 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110039d5b40 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:757 default_idle_call+0x74/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147 CPU: 0 UID: 0 PID: 6571 Comm: syz.2.153 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x3c/0x70 kernel/kcov.c:220 Code: 8b 15 88 22 e1 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 3c 16 00 00 00 74 2c 8b 91 18 16 00 00 83 fa 02 75 21 <48> 8b 91 20 16 00 00 48 8b 32 48 8d 7e 01 8b 89 1c 16 00 00 48 39 RSP: 0018:ffffc9001b8270d8 EFLAGS: 00000246 RAX: ffffffff8a226534 RBX: 0000000003000000 RCX: ffff888033a51e00 RDX: 0000000000000002 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc9001b827230 R08: 0000000000000000 R09: ffffffff8a2262a0 R10: dffffc0000000000 R11: fffff52003704e0c R12: dffffc0000000000 R13: ffff888032dbc000 R14: 0000000002000000 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff888125c13000(0063) knlGS:00000000f54deb40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 0000000080000200 CR3: 00000000755c6000 CR4: 00000000003526f0 Call Trace: xfrm_state_lookup_spi_proto net/xfrm/xfrm_state.c:1707 [inline] xfrm_alloc_spi+0x534/0xf30 net/xfrm/xfrm_state.c:2589 xfrm_alloc_userspi+0x70b/0xc90 net/xfrm/xfrm_user.c:1873 xfrm_user_rcv_msg+0x7a3/0xab0 net/xfrm/xfrm_user.c:3501 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552 xfrm_netlink_rcv+0x79/0x90 net/xfrm/xfrm_user.c:3523 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:729 ____sys_sendmsg+0x505/0x830 net/socket.c:2614 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668 __sys_sendmsg+0x164/0x220 net/socket.c:2700 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xb6/0x2b0 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf70ee539 Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f54de55c EFLAGS: 00000206 ORIG_RAX: 0000000000000172 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000080000200 RDX: 0000000024000014 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000