GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4690/1:b..l rcu: (detected by 1, t=10503 jiffies, g=11505, q=1914999 ncpus=2) task:udevd state:R running task stack:21664 pid:4690 tgid:4690 ppid:1 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6682 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7004 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:memcpy_orig+0x9f/0x140 arch/x86/lib/memcpy_64.S:120 Code: 8d 76 e0 4c 89 47 f8 4c 89 4f f0 4c 89 57 e8 4c 89 5f e0 48 8d 7f e0 73 d2 83 c2 20 48 29 d6 48 29 d7 83 fa 10 72 34 4c 8b 06 <4c> 8b 4e 08 4c 8b 54 16 f0 4c 8b 5c 16 f8 4c 89 07 4c 89 4f 08 4c RSP: 0018:ffffc9000322fa50 EFLAGS: 00000246 RAX: ffffc9000322fc80 RBX: ffff888030205648 RCX: ffffffff821571ec RDX: 0000000000000010 RSI: ffff888030205688 RDI: ffffc9000322fc80 RBP: dffffc0000000000 R08: ffff88801e2938a0 R09: 1ffff92000645f91 R10: dffffc0000000000 R11: fffff52000645f92 R12: ffffc9000322fc88 R13: 000000000000000a R14: 1ffff11006040ac9 R15: ffffc9000322fc60 set_root+0x1ec/0x3c0 fs/namei.c:955 nd_jump_root+0x2a6/0x420 fs/namei.c:975 path_init+0x3cd/0x1360 fs/namei.c:2482 path_lookupat+0x27/0x450 fs/namei.c:2570 filename_lookup+0x256/0x610 fs/namei.c:2609 do_readlinkat+0xf0/0x3a0 fs/stat.c:537 __do_sys_readlink fs/stat.c:574 [inline] __se_sys_readlink fs/stat.c:571 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:571 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f64b9d17d47 RSP: 002b:00007ffe8e34ab18 EFLAGS: 00000246 ORIG_RAX: 0000000000000059 RAX: ffffffffffffffda RBX: 00007ffe8e34ab28 RCX: 00007f64b9d17d47 RDX: 0000000000000400 RSI: 00007ffe8e34ab28 RDI: 00007ffe8e34b008 RBP: 0000000000000400 R08: 0000558e41888204 R09: 0000000000000000 R10: 0000000000000812 R11: 0000000000000246 R12: 00007ffe8e34b008 R13: 00007ffe8e34af78 R14: 0000558e41867910 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10409 jiffies! g11505 f0x2 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:25888 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 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 5312 Comm: kworker/1:6 Not tainted 6.12.0-rc2-syzkaller-00631-g6d858708d465 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events nsim_dev_trap_report_work RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:55 [inline] RIP: 0010:unwind_next_frame+0x1803/0x22d0 arch/x86/kernel/unwind_orc.c:665 Code: 3c 20 00 74 0a 48 8b 7c 24 78 e8 b8 19 bd 00 4c 8b 7d 38 48 8d 7d 08 48 89 f8 48 c1 e8 03 42 80 3c 20 00 74 05 e8 9d 19 bd 00 <4c> 8b 75 08 48 8d 5d 10 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 RSP: 0018:ffffc90000a176d0 EFLAGS: 00000246 RAX: 1ffff92000142ef5 RBX: ffffffff912b51dc RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffc90000a11000 RDI: ffffc90000a177a8 RBP: ffffc90000a177a0 R08: ffffc90000a17cb0 R09: 0000000000000000 R10: ffffc90000a177f0 R11: fffff52000142f00 R12: dffffc0000000000 R13: ffffc90000a177a0 R14: ffffffff8a1f4653 R15: ffffc90000a17cc0 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe4f4f4e6c CR3: 0000000063064000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4085 [inline] slab_alloc_node mm/slub.c:4134 [inline] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4141 dst_alloc+0x12b/0x190 net/core/dst.c:89 rt_dst_alloc net/ipv4/route.c:1612 [inline] __mkroute_output net/ipv4/route.c:2571 [inline] ip_route_output_key_hash_rcu+0x13cc/0x2390 net/ipv4/route.c:2793 ip_route_output_key_hash+0x193/0x2b0 net/ipv4/route.c:2622 __ip_route_output_key include/net/route.h:141 [inline] ip_route_output_flow+0x29/0x140 net/ipv4/route.c:2850 ip_route_output_key include/net/route.h:151 [inline] ip_route_me_harder+0x877/0x1360 net/ipv4/netfilter.c:53 synproxy_send_tcp+0x356/0x6c0 net/netfilter/nf_synproxy_core.c:431 synproxy_send_client_synack+0x8b8/0xf30 net/netfilter/nf_synproxy_core.c:484 nft_synproxy_eval_v4+0x3ca/0x610 net/netfilter/nft_synproxy.c:59 nft_synproxy_do_eval+0x362/0xa60 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288 nft_do_chain_inet+0x418/0x6b0 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x29e/0x450 include/linux/netfilter.h:312 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5668 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5781 process_backlog+0x662/0x15b0 net/core/dev.c:6113 __napi_poll+0xcb/0x490 net/core/dev.c:6834 napi_poll net/core/dev.c:6903 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:7025 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 spin_unlock_bh include/linux/spinlock.h:396 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline] nsim_dev_trap_report_work+0x75d/0xaa0 drivers/net/netdevsim/dev.c:850 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 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 GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog