bridge0: port 2(bridge_slave_1) entered forwarding state bridge0: topology change detected, propagating bridge0: port 1(bridge_slave_0) 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): P5837/1:b..l P136/1:b..l rcu: (detected by 0, t=10502 jiffies, g=24885, q=585 ncpus=2) task:kworker/u8:5 state:R running task stack:24768 pid:136 tgid:136 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5352 [inline] __schedule+0x1665/0x5590 kernel/sched/core.c:6964 preempt_schedule_notrace+0x57/0x90 kernel/sched/core.c:7242 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:753 rcu_read_unlock include/linux/rcupdate.h:879 [inline] __rhashtable_remove_fast include/linux/rhashtable.h:1147 [inline] rhashtable_remove_fast include/linux/rhashtable.h:1171 [inline] netlink_remove net/netlink/af_netlink.c:598 [inline] netlink_release+0xb86/0x1ad0 net/netlink/af_netlink.c:725 __sock_release+0x1f0/0x250 net/socket.c:725 genl_pernet_exit+0x40/0x70 net/netlink/genetlink.c:1901 ops_exit_list net/core/net_namespace.c:199 [inline] ops_undo_list+0x49f/0x940 net/core/net_namespace.c:252 cleanup_net+0x56b/0x800 net/core/net_namespace.c:704 process_one_work+0x9ab/0x1780 kernel/workqueue.c:3289 process_scheduled_works kernel/workqueue.c:3380 [inline] worker_thread+0xba8/0x11e0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:syz-executor state:R running task stack:20952 pid:5837 tgid:5837 ppid:5832 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5352 [inline] __schedule+0x1665/0x5590 kernel/sched/core.c:6964 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7292 irqentry_exit+0x5e4/0x700 kernel/entry/common.c:240 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x20b/0x2e0 kernel/locking/lockdep.c:5872 Code: e9 30 ff ff ff e8 25 6f 1c 0a f7 c3 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 d1 fb c0 11 48 3b 44 24 30 75 33 fb 48 83 c4 38 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 4e b3 b4 RSP: 0018:ffffc90003cf7898 EFLAGS: 00000282 RAX: 00df217719770100 RBX: 0000000000000246 RCX: 0000000000000046 RDX: 000000005a44979c RSI: ffffffff8e4cc981 RDI: ffffffff8c4a6280 RBP: 0000000000000000 R08: ffffffff81778bb5 R09: ffffffff8eb5d6a0 R10: ffffc90003cf7a08 R11: fffff5200079ef4d R12: 0000000000000002 R13: ffffffff8eb5d6a0 R14: 0000000000000000 R15: 0000000000000000 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+0xc2/0x23c0 arch/x86/kernel/unwind_orc.c:495 __unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:773 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6242 [inline] kmem_cache_free+0x189/0x640 mm/slub.c:6369 free_filename fs/namei.c:147 [inline] putname fs/namei.c:306 [inline] class_filename_destructor include/linux/fs.h:2539 [inline] class_filename_flags_destructor include/linux/fs.h:2541 [inline] user_path_at+0xd4/0x160 fs/namei.c:3638 ksys_umount fs/namespace.c:2062 [inline] __do_sys_umount fs/namespace.c:2070 [inline] __se_sys_umount fs/namespace.c:2068 [inline] __x64_sys_umount+0xf6/0x170 fs/namespace.c:2068 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3c5a99d9d7 RSP: 002b:00007ffcd1b6f8d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3c5a99d9d7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcd1b6f990 RBP: 00007ffcd1b6f990 R08: 00007ffcd1b70990 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcd1b70a20 R13: 00007f3c5aa32050 R14: 0000000000020051 R15: 00007ffcd1b70a60 rcu: rcu_preempt kthread starved for 10553 jiffies! g24885 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:28008 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5352 [inline] __schedule+0x1665/0x5590 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7047 [inline] schedule+0x164/0x360 kernel/sched/core.c:7062 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 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: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: fd 91 02 e9 d3 f1 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 13 12 2a 00 fb f4 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffffff8e807dc0 EFLAGS: 00000246 RAX: 0000000000b3804d RBX: ffffffff819bd2ea RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8e257836 RDI: ffffffff8c4a6280 RBP: ffffffff8e807eb0 R08: ffff8880b843399b R09: 1ffff11017086733 R10: dffffc0000000000 R11: ffffed1017086734 R12: ffffffff905441f0 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1d125d8 FS: 0000000000000000(0000) GS:ffff888124de2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa5ee5e9e80 CR3: 000000002c680000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1ba/0x5d0 kernel/sched/idle.c:341 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:439 rest_init+0x2de/0x300 init/main.c:762 start_kernel+0x38f/0x3e0 init/main.c:1214 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147