bridge0: port 2(team0) entered forwarding state bridge0: topology change detected, propagating rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10702/1:b..l rcu: (detected by 0, t=10502 jiffies, g=37625, q=1368 ncpus=1) task:syz.1.990 state:R running task stack:24368 pid:10702 tgid:10688 ppid:5831 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6911 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7238 irqentry_exit+0x17b/0x670 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:kasan_check_range+0x12/0x1e0 mm/kasan/generic.c:199 Code: 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 48 85 f6 0f 84 7a 01 00 00 48 89 f8 41 54 <41> 89 d0 48 01 f0 55 53 0f 82 e6 00 00 00 eb 0f cc cc cc 48 b8 00 RSP: 0018:ffffc900051cf178 EFLAGS: 00000202 RAX: ffff888022b15164 RBX: ffff888022b15000 RCX: ffffffff84dbc943 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff888022b15164 RBP: ffff888022b15164 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffffffffffff R15: 0000000000000000 instrument_atomic_read include/linux/instrumented.h:82 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] blk_cgroup_congested+0xb3/0x270 block/blk-cgroup.c:2240 __folio_throttle_swaprate+0x3d/0x190 mm/swapfile.c:3924 folio_throttle_swaprate include/linux/swap.h:587 [inline] do_swap_page+0x1ceb/0x6900 mm/memory.c:4876 __collapse_huge_page_swapin+0x112/0x6d0 mm/khugepaged.c:1014 collapse_huge_page+0x551/0x38c0 mm/khugepaged.c:1124 hpage_collapse_scan_pmd+0xdb9/0x1670 mm/khugepaged.c:1392 madvise_collapse+0x6ee/0xbe0 mm/khugepaged.c:2824 madvise_vma_behavior+0x1987/0x3050 mm/madvise.c:1370 madvise_walk_vmas+0x2fe/0xa90 mm/madvise.c:1719 madvise_do_behavior+0x1ea/0x510 mm/madvise.c:1935 do_madvise+0x195/0x240 mm/madvise.c:2028 __do_sys_madvise mm/madvise.c:2037 [inline] __se_sys_madvise mm/madvise.c:2035 [inline] __x64_sys_madvise+0xa9/0x110 mm/madvise.c:2035 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7736b9c799 RSP: 002b:00007f7737a54028 EFLAGS: 00000246 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 00007f7736e16180 RCX: 00007f7736b9c799 RDX: 0000000000000019 RSI: ffffffffffff0005 RDI: 0000000000000000 RBP: 00007f7736c32c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7736e16218 R14: 00007f7736e16180 R15: 00007ffdedb574d8 rcu: rcu_preempt kthread starved for 234 jiffies! g37625 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:28672 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7008 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 3413 Comm: kworker/R-bat_e Tainted: G U L syzkaller #0 PREEMPT(full) Tainted: [U]=USER, [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: bat_events batadv_tt_purge RIP: 0010:lock_acquire+0x5e/0x380 kernel/locking/lockdep.c:5872 Code: 05 3b 0f 29 12 83 f8 07 0f 87 f0 00 00 00 48 0f a3 05 06 6b f5 0e 0f 82 c2 02 00 00 8b 35 ce 9e f5 0e 85 f6 0f 85 dd 00 00 00 <48> 8b 44 24 30 65 48 2b 05 dd 0e 29 12 0f 85 02 03 00 00 48 83 c4 RSP: 0018:ffffc90000006eb8 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000003 RDX: 0000000000000000 RSI: ffffffff8de5a083 RDI: ffffffff8c1b0aa0 RBP: ffffffff8e7e7660 R08: 0000000006fa0785 R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124349000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7d373a9e9c CR3: 0000000077df4000 CR4: 00000000003526f0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4538 [inline] slab_alloc_node mm/slub.c:4866 [inline] kmem_cache_alloc_noprof+0x241/0x6e0 mm/slub.c:4873 skb_clone+0x190/0x400 net/core/skbuff.c:2120 deliver_clone net/bridge/br_forward.c:125 [inline] br_flood+0x35c/0x650 net/bridge/br_forward.c:250 br_handle_frame_finish+0xff4/0x1f60 net/bridge/br_input.c:229 br_nf_hook_thresh+0x30d/0x420 net/bridge/br_netfilter_hooks.c:1167 br_nf_pre_routing_finish_ipv6+0x769/0xfb0 net/bridge/br_netfilter_ipv6.c:154 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x39c/0x8b0 net/bridge/br_netfilter_ipv6.c:184 br_nf_pre_routing+0x90d/0x1550 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0xcdd/0x1520 net/bridge/br_input.c:442 __netif_receive_skb_core.constprop.0+0x6c5/0x3550 net/core/dev.c:6051 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6162 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6277 process_backlog+0x37a/0x1580 net/core/dev.c:6628 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7692 napi_poll net/core/dev.c:7755 [inline] net_rx_action+0xa40/0xf20 net/core/dev.c:7912 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622 do_softirq kernel/softirq.c:523 [inline] do_softirq+0xac/0xe0 kernel/softirq.c:510 __local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:395 [inline] batadv_tt_local_purge+0x21c/0x3d0 net/batman-adv/translation-table.c:1315 batadv_tt_purge+0x8b/0xbd0 net/batman-adv/translation-table.c:3509 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] rescuer_thread+0x905/0x14a0 kernel/workqueue.c:3583 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245