rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5961/3:b..l rcu: (detected by 0, t=10503 jiffies, g=7345, q=1288 ncpus=2) task:syz.1.14 state:R running task stack:25184 pid:5961 tgid:5960 ppid:5838 flags:0x00000006 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7078 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:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 89 fb e8 23 00 00 00 48 8b 3d f4 c0 8f 0c 48 89 de 5b e9 a3 fc 5a 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 c0 d5 03 00 65 8b 15 40 53 RSP: 0018:ffffc9000445f510 EFLAGS: 00000246 RAX: 0000000000000005 RBX: ffff888033287348 RCX: 0000000000080000 RDX: ffffc9000c141000 RSI: 000000000000d8ad RDI: 000000000000d8ae RBP: 0000000000000001 R08: 0000000000000001 R09: ffffffff89de6d77 R10: 0000000000000004 R11: ffff88802a801e00 R12: ffffc9000445f5c0 R13: 0000000000000005 R14: ffff888033287350 R15: 1ffff11006650e60 nf_hook_slow+0x181/0x220 net/netfilter/core.c:625 nf_hook+0x2c4/0x450 include/linux/netfilter.h:269 __ip_local_out+0x3d9/0x4e0 net/ipv4/ip_output.c:119 ip_local_out net/ipv4/ip_output.c:128 [inline] __ip_queue_xmit+0x122e/0x1d50 net/ipv4/ip_output.c:528 l2tp_ip_sendmsg+0x66f/0x1680 net/l2tp/l2tp_ip.c:518 sock_sendmsg_nosec net/socket.c:713 [inline] __sock_sendmsg+0x1a6/0x270 net/socket.c:728 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2568 ___sys_sendmsg net/socket.c:2622 [inline] __sys_sendmmsg+0x36a/0x720 net/socket.c:2711 __do_sys_sendmmsg net/socket.c:2738 [inline] __se_sys_sendmmsg net/socket.c:2735 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2735 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: 0033:0x7f975ed85d29 RSP: 002b:00007f975fb27038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f975ef75fa0 RCX: 00007f975ed85d29 RDX: 00000000040000cf RSI: 0000000020000900 RDI: 0000000000000003 RBP: 00007f975ee01b08 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f975ef75fa0 R15: 00007ffc2369d6b8 rcu: rcu_preempt kthread starved for 6047 jiffies! g7345 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:25624 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 24 Comm: ksoftirqd/1 Not tainted 6.13.0-rc7-syzkaller-01131-g8d20dcda404d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:102 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline] RIP: 0010:unwind_next_frame+0x6f2/0x22d0 arch/x86/kernel/unwind_orc.c:494 Code: b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 27 48 63 03 48 01 d8 48 8d 4b 04 4c 39 f8 4c 0f 46 f1 48 8d 43 fc 48 0f 47 e8 <4c> 0f 46 e3 49 39 ee 76 a9 e9 55 fb ff ff 89 d9 80 e1 07 80 c1 03 RSP: 0018:ffffc900001e5b10 EFLAGS: 00000283 RAX: ffffffff908376d4 RBX: ffffffff908376d8 RCX: ffffffff908376dc RDX: 00000000000b0001 RSI: ffffffff912546fa RDI: 0000000000000001 RBP: ffffffff908376d8 R08: 0000000000000001 R09: ffffc900001e5cd0 R10: ffffc900001e5c30 R11: ffffffff818b4af0 R12: ffffffff908376d8 R13: ffffffff908376d8 R14: ffffffff908376dc R15: ffffffff89989a21 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020002038 CR3: 000000002fa54000 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:250 [inline] slab_post_alloc_hook mm/slub.c:4119 [inline] slab_alloc_node mm/slub.c:4168 [inline] kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4175 skb_clone+0x20c/0x390 net/core/skbuff.c:2084 dev_queue_xmit_nit+0x249/0xca0 net/core/dev.c:2472 xmit_one net/core/dev.c:3743 [inline] dev_hard_start_xmit+0x15f/0x7d0 net/core/dev.c:3763 __dev_queue_xmit+0x1b73/0x3f50 net/core/dev.c:4593 dev_queue_xmit include/linux/netdevice.h:3296 [inline] br_dev_queue_push_xmit+0x726/0x900 net/bridge/br_forward.c:53 NF_HOOK+0x700/0x7c0 include/linux/netfilter.h:314 br_nf_post_routing+0xa20/0xe80 net/bridge/br_netfilter_hooks.c:997 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+0x2a7/0x460 include/linux/netfilter.h:312 br_forward_finish+0xd8/0x130 net/bridge/br_forward.c:66 br_nf_forward_finish+0xb49/0xfb0 net/bridge/br_netfilter_hooks.c:693 NF_HOOK+0x700/0x7c0 include/linux/netfilter.h:314 br_nf_forward_ip+0x61e/0x7b0 net/bridge/br_netfilter_hooks.c:747 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+0x2a7/0x460 include/linux/netfilter.h:312 __br_forward+0x489/0x660 net/bridge/br_forward.c:115 br_handle_frame_finish+0x18d2/0x2000 net/bridge/br_input.c:220 br_nf_hook_thresh+0x472/0x590 br_nf_pre_routing_finish_ipv6+0xaa0/0xdd0 NF_HOOK include/linux/netfilter.h:314 [inline] br_nf_pre_routing_ipv6+0x379/0x770 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_bridge_pre net/bridge/br_input.c:282 [inline] br_handle_frame+0x9f3/0x1530 net/bridge/br_input.c:433 __netif_receive_skb_core+0x13e7/0x4540 net/core/dev.c:5731 __netif_receive_skb_one_core net/core/dev.c:5835 [inline] __netif_receive_skb+0x12f/0x650 net/core/dev.c:5950 process_backlog+0x662/0x15b0 net/core/dev.c:6298 __napi_poll+0xcb/0x490 net/core/dev.c:7115 napi_poll net/core/dev.c:7184 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:7306 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561 run_ksoftirqd+0xca/0x130 kernel/softirq.c:950 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 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 net_ratelimit: 20339 callbacks suppressed bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:66:bd:22:26:be:d8, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:66:bd:22:26:be:d8, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:66:bd:22:26:be:d8, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) net_ratelimit: 23885 callbacks suppressed bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:66:bd:22:26:be:d8, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:66:bd:22:26:be:d8, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:66:bd:22:26:be:d8, vlan:0)