rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=27105, q=989 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 9440 (4294973374-4294963934), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 9440 jiffies! g27105 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:27272 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: CPU: 1 PID: 7615 Comm: syz.1.379 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:get_stack_pointer arch/x86/include/asm/stacktrace.h:-1 [inline] RIP: 0010:unwind_start arch/x86/include/asm/unwind.h:62 [inline] RIP: 0010:arch_stack_walk+0x80/0x190 arch/x86/kernel/stacktrace.c:24 Code: 48 8b 05 23 99 d1 7e 49 39 c4 74 19 e8 d9 83 53 00 49 8b 8c 24 98 18 00 00 eb 12 e8 ca 83 53 00 e9 f3 00 00 00 e8 c0 83 53 00 <48> 89 e9 48 c7 45 d0 00 00 00 00 48 c7 45 c8 00 00 00 00 48 c7 45 RSP: 0018:ffffc900001efb48 EFLAGS: 00000246 RAX: ffffffff81321cc0 RBX: ffffc900001efc00 RCX: ffff888079509e00 RDX: 0000000000000100 RSI: ffffc900001efc00 RDI: ffffffff81747d20 RBP: ffffc900001efbd0 R08: ffffc900001efd3f R09: 0000000000000000 R10: ffffc900001efcc0 R11: fffff5200003dfa8 R12: ffff888079509e00 R13: 1ffff9200003df94 R14: ffffffff81747d20 R15: 0000000000000000 FS: 00007f6a7b8ca6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000002000 CR3: 0000000047491000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf7/0x1f0 mm/page_owner.c:128 __set_page_owner+0x1d/0x60 mm/page_owner.c:192 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554 prep_new_page mm/page_alloc.c:1561 [inline] get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457 alloc_slab_page+0x5d/0x170 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2e0 mm/slub.c:2081 ___slab_alloc+0xc6d/0x1300 mm/slub.c:3253 __slab_alloc mm/slub.c:3339 [inline] __slab_alloc_node mm/slub.c:3392 [inline] slab_alloc_node mm/slub.c:3485 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x1b7/0x2e0 mm/slub.c:3519 skb_clone+0x1eb/0x370 net/core/skbuff.c:1915 deliver_clone net/bridge/br_forward.c:125 [inline] br_flood+0x415/0x680 net/bridge/br_forward.c:246 br_handle_frame_finish+0x143d/0x1950 net/bridge/br_input.c:215 br_nf_hook_thresh+0x3b6/0x480 net/bridge/br_netfilter_hooks.c:1184 br_nf_pre_routing_finish_ipv6+0x9e3/0xd90 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:304 [inline] br_nf_pre_routing_ipv6+0x34d/0x680 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline] nf_hook_bridge_pre net/bridge/br_input.c:277 [inline] br_handle_frame+0x957/0x14c0 net/bridge/br_input.c:424 __netif_receive_skb_core+0xf6b/0x3ac0 net/core/dev.c:5502 __netif_receive_skb_one_core net/core/dev.c:5606 [inline] __netif_receive_skb+0x74/0x290 net/core/dev.c:5722 process_backlog+0x380/0x6e0 net/core/dev.c:6050 __napi_poll+0xc0/0x460 net/core/dev.c:6612 napi_poll net/core/dev.c:6679 [inline] net_rx_action+0x5ea/0xbf0 net/core/dev.c:6815 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:preempt_schedule_irq+0xb0/0x140 kernel/sched/core.c:7009 Code: 44 24 20 f6 44 24 21 02 74 0b 0f 0b 48 f7 03 08 00 00 00 74 63 bf 01 00 00 00 e8 6b f6 e3 f6 e8 c6 7c 14 f7 fb bf 01 00 00 00 db b5 ff ff 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 8b 44 24 RSP: 0018:ffffc90003897b40 EFLAGS: 00000286 RAX: ee557348e5a10200 RBX: 0000000000000000 RCX: ee557348e5a10200 RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: 0000000000000001 RBP: ffffc90003897be0 R08: ffffffff8e4a8e2f R09: 1ffffffff1c951c5 R10: dffffc0000000000 R11: fffffbfff1c951c6 R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000712f68 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:percpu_counter_add_batch+0x235/0x280 lib/percpu_counter.c:103 Code: 4d 85 f6 75 16 e8 fb 64 35 fd eb 15 e8 f4 64 35 fd e8 1f 02 1f 06 4d 85 f6 74 ea e8 e5 64 35 fd fb 48 c7 44 24 40 0e 36 e0 45 <48> 8b 44 24 38 4a c7 04 38 00 00 00 00 66 42 c7 44 38 09 00 00 42 RSP: 0018:ffffc90003897ca0 EFLAGS: 00000287 RAX: ffffffff84503b9b RBX: 0000000000000000 RCX: 0000000000080000 RDX: ffffc90010101000 RSI: 000000000000479b RDI: 000000000000479c RBP: ffffc90003897d90 R08: ffffffff8e4a8e2f R09: 1ffffffff1c951c5 R10: dffffc0000000000 R11: fffffbfff1c951c6 R12: 1ffffffff2e57f6b R13: 0000000000000006 R14: 0000000000000200 R15: dffffc0000000000 sk_sockets_allocated_inc include/net/sock.h:1511 [inline] mptcp_init_sock+0x298/0x3c0 net/mptcp/protocol.c:2909 inet_create+0xcf7/0xfe0 net/ipv4/af_inet.c:383 __sock_create+0x4a6/0x940 net/socket.c:1571 sock_create net/socket.c:1627 [inline] __sys_socket_create net/socket.c:1664 [inline] __sys_socket+0xd7/0x1a0 net/socket.c:1715 __do_sys_socket net/socket.c:1729 [inline] __se_sys_socket net/socket.c:1727 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1727 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: 0033:0x7f6a7a98f749 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:00007f6a7b8ca038 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 00007f6a7abe5fa0 RCX: 00007f6a7a98f749 RDX: 0000000000000106 RSI: 0000922000000001 RDI: 0000000000000002 RBP: 00007f6a7aa13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6a7abe6038 R14: 00007f6a7abe5fa0 R15: 00007fffda8ecc78 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:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:5a:a1:29:c8:ac:60, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:5a:a1:29:c8:ac:60, 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:5a:a1:29:c8:ac:60, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:5a:a1:29:c8:ac:60, 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:1b, vlan:0)