rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10494 ticks this GP) idle=701c/1/0x4000000000000000 softirq=13298/13299 fqs=2 rcu: (t=10500 jiffies g=12369 q=437 ncpus=2) rcu: rcu_preempt kthread starved for 10495 jiffies! g12369 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:27088 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 6324 Comm: syz.3.123 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:148 Code: cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d c3 64 39 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 66 0f 1f 00 55 41 57 41 56 RSP: 0000:ffffc90005577878 EFLAGS: 000002d3 RAX: ffffffff813a13aa RBX: 0000000000000003 RCX: ffff888079ab8000 RDX: 0000000000000000 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6b00 RBP: ffffc90005577950 R08: ffffffff90da85d7 R09: 1ffffffff21b50ba R10: dffffc0000000000 R11: fffffbfff21b50bb R12: dffffc0000000000 R13: 0000000000000200 R14: 0000000000000003 R15: 1ffff92000aaef14 FS: 000055557daeb500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe278bd6620 CR3: 000000007d9a6000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline] kvm_wait+0x22f/0x290 arch/x86/kernel/kvm.c:1058 pv_wait arch/x86/include/asm/paravirt.h:598 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline] __pv_queued_spin_lock_slowpath+0x61a/0x9d0 kernel/locking/qspinlock.c:511 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:586 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x24e/0x2c0 kernel/locking/spinlock_debug.c:115 spin_lock include/linux/spinlock.h:351 [inline] futex_unqueue+0x4e/0xf0 kernel/futex/core.c:597 futex_wait+0x1a7/0x530 kernel/futex/waitwake.c:660 do_futex+0x2ff/0x3e0 kernel/futex/syscalls.c:106 __do_sys_futex kernel/futex/syscalls.c:183 [inline] __se_sys_futex+0x36f/0x3f0 kernel/futex/syscalls.c:164 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fe127f8f6c9 Code: 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 01 48 RSP: 002b:00007ffc39978308 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 000000000001916e RCX: 00007fe127f8f6c9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fe1281e5fac RBP: 0000000000000032 R08: 0000000000745d1e R09: 00000003399785ff R10: 00007ffc39978400 R11: 0000000000000246 R12: 00007fe1281e5fac R13: 00007ffc39978400 R14: 00000000000191a0 R15: 00007ffc39978420 CPU: 0 PID: 6327 Comm: syz.3.123 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:seqcount_lockdep_reader_access+0x17f/0x1c0 include/linux/seqlock.h:105 Code: 00 4d 85 e4 75 16 e8 d0 8f 0f 00 eb 15 e8 c9 8f 0f 00 e8 e4 cd f8 08 4d 85 e4 74 ea e8 ba 8f 0f 00 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3e 00 00 00 00 66 43 c7 44 3e 09 00 00 43 c6 44 3e 0b 00 RSP: 0018:ffffc90000006820 EFLAGS: 00000246 RAX: ffffffff8175ffd6 RBX: 0000000000000000 RCX: ffff88805b881e00 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900000068d8 R08: ffffffff90da8607 R09: 1ffffffff21b50c0 R10: dffffc0000000000 R11: fffffbfff21b50c1 R12: 0000000000000200 R13: 000001fb63109b96 R14: 1ffff92000000d04 R15: dffffc0000000000 FS: 00007fe128f0d6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000100000000 CR3: 000000007d9a6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: ktime_get_with_offset+0x94/0x330 kernel/time/timekeeping.c:889 ktime_get_real include/linux/timekeeping.h:79 [inline] netif_rx_internal+0x34a/0x4e0 net/core/dev.c:5115 __netif_rx+0x78/0xc0 net/core/dev.c:5158 veth_forward_skb drivers/net/veth.c:321 [inline] veth_xmit+0x550/0x9f0 drivers/net/veth.c:374 __netdev_start_xmit include/linux/netdevice.h:4943 [inline] netdev_start_xmit include/linux/netdevice.h:4957 [inline] xmit_one net/core/dev.c:3619 [inline] dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3635 __dev_queue_xmit+0x1a64/0x35a0 net/core/dev.c:4425 dev_queue_xmit include/linux/netdevice.h:3113 [inline] br_dev_queue_push_xmit+0x6a6/0x850 net/bridge/br_forward.c:53 NF_HOOK+0x340/0x3d0 include/linux/netfilter.h:304 br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66 NF_HOOK+0x340/0x3d0 include/linux/netfilter.h:304 __br_forward+0x41f/0x600 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver+0xb5/0x150 net/bridge/br_forward.c:190 br_flood+0x31b/0x680 net/bridge/br_forward.c:236 br_dev_xmit+0x1176/0x17f0 net/bridge/br_device.c:106 __netdev_start_xmit include/linux/netdevice.h:4943 [inline] netdev_start_xmit include/linux/netdevice.h:4957 [inline] xmit_one net/core/dev.c:3619 [inline] dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3635 __dev_queue_xmit+0x1a64/0x35a0 net/core/dev.c:4425 dev_queue_xmit include/linux/netdevice.h:3113 [inline] neigh_hh_output include/net/neighbour.h:527 [inline] neigh_output include/net/neighbour.h:541 [inline] ip6_finish_output2+0xdf5/0x1650 net/ipv6/ip6_output.c:141 dst_output include/net/dst.h:467 [inline] NF_HOOK include/linux/netfilter.h:304 [inline] ndisc_send_skb+0xbed/0x14b0 net/ipv6/ndisc.c:513 addrconf_rs_timer+0x2bc/0x600 net/ipv6/addrconf.c:4006 call_timer_fn+0x16e/0x530 kernel/time/timer.c:1700 expire_timers kernel/time/timer.c:1751 [inline] __run_timers+0x52d/0x7d0 kernel/time/timer.c:2022 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:plist_del+0x0/0x3f0 lib/plist.c:113 Code: f1 80 e1 07 80 c1 03 38 c1 0f 8c f5 fc ff ff 4c 89 f7 e8 83 94 7e f7 e9 e8 fc ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <66> 0f 1f 00 55 41 57 41 56 41 55 41 54 53 48 83 ec 28 48 89 f3 49 RSP: 0018:ffffc9001894fba8 EFLAGS: 00000246 RAX: ffffffff8179c7ff RBX: ffffc90005577c50 RCX: 0000000000080000 RDX: ffffc9000cbfa000 RSI: ffffc90000a3e3c8 RDI: ffffc90005577c50 RBP: 0000000000000001 R08: ffff888079ab802b R09: 1ffff1100f357005 R10: dffffc0000000000 R11: ffffed100f357006 R12: dffffc0000000000 R13: ffffc90005577c80 R14: ffffc90000a3e380 R15: ffffc90000a3e388 __futex_unqueue+0xf0/0x160 kernel/futex/core.c:518 futex_wake_mark+0xec/0x150 kernel/futex/waitwake.c:123 futex_wake+0x315/0x4b0 kernel/futex/waitwake.c:177 do_futex+0x35d/0x3e0 kernel/futex/syscalls.c:111 __do_sys_futex kernel/futex/syscalls.c:183 [inline] __se_sys_futex+0x36f/0x3f0 kernel/futex/syscalls.c:164 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fe127f8f6c9 Code: 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 01 48 RSP: 002b:00007fe128f0d0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007fe1281e5fa8 RCX: 00007fe127f8f6c9 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fe1281e5fac RBP: 00007fe1281e5fa0 R08: 0000000000745d1e R09: 0000000000000000 R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe1281e6038 R14: 00007ffc399780c0 R15: 00007ffc399781a8