GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (4 ticks this GP) idle=b48c/1/0x4000000000000000 softirq=10775/10775 fqs=0 rcu: (detected by 0, t=10502 jiffies, g=6701, q=1011 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5226 Comm: udevd Not tainted 6.12.0-rc3-syzkaller-00140-g07d6bf634bc8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:validate_chain+0x60f/0x5920 kernel/locking/lockdep.c:3916 Code: 00 00 00 00 41 c6 44 0c 33 00 65 48 8b 0c 25 28 00 00 00 48 3b 8c 24 a0 02 00 00 0f 85 07 50 00 00 48 8d 65 d8 5b 41 5c 41 5d <41> 5e 41 5f 5d c3 cc cc cc cc 83 fb 03 41 b9 02 00 00 00 44 0f 4d RSP: 0018:ffffc90000a168d0 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffffffff93c43190 RCX: 64f107b1a92f2200 RDX: 0000000000000001 RSI: ffff88802dab65f8 RDI: ffff88802dab5a00 RBP: ffffc90000a168e0 R08: ffffffff942c9807 R09: 1ffffffff2859300 R10: dffffc0000000000 R11: fffffbfff2859301 R12: 0000000000000001 R13: ffff88802dab64d8 R14: e3a7f52acf58201d R15: ffff88802dab6618 FS: 00007ff02a6d1c80(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb455e656c0 CR3: 0000000070c2c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] advance_sched+0xa1e/0xca0 net/sched/sch_taprio.c:985 __run_hrtimer kernel/time/hrtimer.c:1691 [inline] __hrtimer_run_queues+0x59b/0xd50 kernel/time/hrtimer.c:1755 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1817 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1026 [inline] __sysvec_apic_timer_interrupt+0x110/0x3f0 arch/x86/kernel/apic/apic.c:1043 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1037 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1037 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__sanitizer_cov_trace_const_cmp2+0x0/0x90 kernel/kcov.c:306 Code: 10 48 89 74 0a 18 4c 89 44 0a 20 c3 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 4c 8b 04 24 65 48 8b 14 25 c0 d7 03 00 65 8b 05 10 ec RSP: 0018:ffffc90000a16f98 EFLAGS: 00000206 RAX: 0000000000000100 RBX: ffffffff8c997bc8 RCX: ffff88802dab5a00 RDX: ffff88802dab5a00 RSI: 0000000000000008 RDI: 0000000000000689 RBP: 0000000000000060 R08: ffffffff8992a8ff R09: ffffffff8992a876 R10: 0000000000000002 R11: ffff88802dab5a00 R12: ffff8880294b1a70 R13: 0000000000000008 R14: 0080010000134829 R15: dffffc0000000000 can_checksum_protocol include/linux/netdevice.h:4845 [inline] harmonize_features net/core/dev.c:3482 [inline] netif_skb_features+0x871/0xc90 net/core/dev.c:3573 validate_xmit_skb+0x88/0x1120 net/core/dev.c:3657 validate_xmit_skb_list+0x95/0x130 net/core/dev.c:3719 sch_direct_xmit+0x108/0x5d0 net/sched/sch_generic.c:328 __dev_xmit_skb net/core/dev.c:3821 [inline] __dev_queue_xmit+0x1a2d/0x3ed0 net/core/dev.c:4394 dev_queue_xmit include/linux/netdevice.h:3094 [inline] neigh_hh_output include/net/neighbour.h:526 [inline] neigh_output include/net/neighbour.h:540 [inline] ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:236 ip_local_out net/ipv4/ip_output.c:130 [inline] __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:536 __tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466 tcp_transmit_skb net/ipv4/tcp_output.c:1484 [inline] tcp_write_xmit+0x17b5/0x6bf0 net/ipv4/tcp_output.c:2827 __tcp_push_pending_frames+0x9b/0x360 net/ipv4/tcp_output.c:3012 tcp_push_pending_frames include/net/tcp.h:2107 [inline] tcp_data_snd_check net/ipv4/tcp_input.c:5741 [inline] tcp_rcv_established+0x1111/0x2020 net/ipv4/tcp_input.c:6175 tcp_v4_do_rcv+0x96d/0xc70 net/ipv4/tcp_ipv4.c:1915 tcp_v4_rcv+0x2dc0/0x37f0 net/ipv4/tcp_ipv4.c:2350 ip_protocol_deliver_rcu+0x22e/0x440 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x341/0x5f0 net/ipv4/ip_input.c:233 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 ip_local_deliver net/ipv4/ip_input.c:254 [inline] dst_input include/net/dst.h:460 [inline] ip_sublist_rcv_finish+0x3be/0x4f0 net/ipv4/ip_input.c:580 ip_list_rcv_finish net/ipv4/ip_input.c:630 [inline] ip_sublist_rcv+0x75d/0xab0 net/ipv4/ip_input.c:638 ip_list_rcv+0x42b/0x480 net/ipv4/ip_input.c:672 __netif_receive_skb_list_ptype net/core/dev.c:5709 [inline] __netif_receive_skb_list_core+0x94e/0x980 net/core/dev.c:5756 __netif_receive_skb_list net/core/dev.c:5808 [inline] netif_receive_skb_list_internal+0xa51/0xe30 net/core/dev.c:5899 gro_normal_list include/net/gro.h:515 [inline] napi_complete_done+0x310/0x8e0 net/core/dev.c:6250 virtqueue_napi_complete drivers/net/virtio_net.c:697 [inline] virtnet_poll+0x2db0/0x3980 drivers/net/virtio_net.c:2831 __napi_poll+0xcb/0x490 net/core/dev.c:6775 napi_poll net/core/dev.c:6844 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6966 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 common_interrupt+0xb9/0xd0 arch/x86/kernel/irq.c:278 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 RIP: 0010:syscall_enter_from_user_mode_work include/linux/entry-common.h:167 [inline] RIP: 0010:syscall_enter_from_user_mode include/linux/entry-common.h:198 [inline] RIP: 0010:do_syscall_64+0xbc/0x230 arch/x86/entry/common.c:79 Code: ed 00 00 00 48 8b 7d 08 e8 f1 64 00 00 0f 1f 44 00 00 0f 1f 44 00 00 90 e8 41 bb d6 f5 90 90 e8 ea ba d6 f5 fb 49 8b 54 24 08 c2 3f 74 0e 4c 89 f7 4c 89 fe e8 04 b2 b8 f5 49 89 c7 90 90 41 RSP: 0018:ffffc900036aff10 EFLAGS: 00000282 RAX: 64f107b1a92f2200 RBX: ffffc900036aff10 RCX: ffffffff9a3d0903 RDX: 0000000000000000 RSI: ffffffff8c0acac0 RDI: ffffffff8c610120 RBP: ffffc900036aff48 R08: ffffffff901cfeaf R09: 1ffffffff2039fd5 R10: dffffc0000000000 R11: fffffbfff2039fd6 R12: ffff88802dab5a00 R13: 0000000000000000 R14: ffffc900036aff58 R15: 0000000000000106 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff02a3165f4 Code: 64 c7 00 09 00 00 00 83 c8 ff c3 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 00 00 00 00 41 89 ca b8 06 01 00 00 0f 05 <45> 31 c0 3d 00 f0 ff ff 76 10 48 8b 15 03 a8 0d 00 f7 d8 41 83 c8 RSP: 002b:00007ffc374c3ca8 EFLAGS: 00000206 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 00007ff02a3ee460 RCX: 00007ff02a3165f4 RDX: 00007ffc374c3cb0 RSI: 00007ff02a3b3130 RDI: 0000000000000009 RBP: 000055e14ae46760 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000001000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000003fff R14: 00007ffc374c4248 R15: 000000000000000a rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g6701 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=2511 rcu: rcu_preempt kthread starved for 10502 jiffies! g6701 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26144 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6682 __schedule_loop kernel/sched/core.c:6759 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6774 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 sched: DL replenish lagged too much