rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5853/1:b..l rcu: (detected by 1, t=10502 jiffies, g=32809, q=1181 ncpus=2) task:syz-executor state:R running task stack:21800 pid:5853 tgid:5853 ppid:5834 task_flags:0x400140 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5351 [inline] __schedule+0x1737/0x4d30 kernel/sched/core.c:6954 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7281 irqentry_exit+0x6f/0x90 kernel/entry/common.c:196 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__nr_to_section include/linux/mmzone.h:1940 [inline] RIP: 0010:__pfn_to_section include/linux/mmzone.h:2075 [inline] RIP: 0010:lookup_page_ext mm/page_ext.c:251 [inline] RIP: 0010:page_ext_lookup+0xae/0x180 mm/page_ext.c:520 Code: 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 b6 f2 f4 ff 4d 8b 36 4d 85 f6 74 1b 48 c1 eb 0f e8 b5 cf 91 ff 83 e3 7f e3 05 49 01 de eb 0f e8 a5 cf 91 ff eb 05 e8 9e cf 91 ff 45 31 RSP: 0018:ffffc9000403fa68 EFLAGS: 00000206 RAX: ffffffff822de0fb RBX: 000000000000000f RCX: ffff888033229e00 RDX: 0000000000000000 RSI: 0000000000001000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff822c266e R10: 000000000000000d R11: ffffffff81ac3450 R12: 000000000007e075 R13: dffffc0000000000 R14: ffff88813fffa400 R15: 0000000000001000 page_ext_iter_begin include/linux/page_ext.h:132 [inline] __update_page_owner_free_handle+0x103/0x470 mm/page_owner.c:272 __reset_page_owner+0x85/0x1f0 mm/page_owner.c:309 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706 discard_slab mm/slub.c:2717 [inline] __put_partials+0x161/0x1c0 mm/slub.c:3186 put_cpu_partial+0x17c/0x250 mm/slub.c:3261 __slab_free+0x2f7/0x400 mm/slub.c:4513 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4204 getname_flags+0xb8/0x540 fs/namei.c:146 user_path_at+0x24/0x60 fs/namei.c:3126 ksys_umount fs/namespace.c:2115 [inline] __do_sys_umount fs/namespace.c:2123 [inline] __se_sys_umount fs/namespace.c:2121 [inline] __x64_sys_umount+0xee/0x160 fs/namespace.c:2121 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe5da38fe97 RSP: 002b:00007ffcbba61ad8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 00007fe5da411bdd RCX: 00007fe5da38fe97 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcbba62c20 RBP: 00007ffcbba62c0c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcbba62c20 R13: 00007fe5da411bdd R14: 0000000000033b84 R15: 00007ffcbba62c60 rcu: rcu_preempt kthread starved for 554 jiffies! g32809 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:26760 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5351 [inline] __schedule+0x1737/0x4d30 kernel/sched/core.c:6954 __schedule_loop kernel/sched/core.c:7036 [inline] schedule+0x165/0x360 kernel/sched/core.c:7051 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 9614 Comm: kworker/u8:27 Not tainted 6.16.0-syzkaller-06600-g1dbf1d590d10 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 89 fb e8 23 00 00 00 48 8b 3d e4 43 fa 0b 48 89 de 5b e9 63 5c 58 00 cc cc cc 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 08 00 9a 92 65 8b 15 68 4f RSP: 0018:ffffc90000007170 EFLAGS: 00000297 RAX: ffffffff8951d6aa RBX: ffff88809f69a780 RCX: 0000000000000100 RDX: ffff88802affda00 RSI: 0000000000000000 RDI: 0000000000000004 RBP: ffff88809f69a7fe R08: ffff88802affda00 R09: 0000000000000003 R10: 0000000000000002 R11: 0000000000000100 R12: dffffc0000000000 R13: 0000000000000820 R14: 1ffff11013ed34ff R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125c80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f68cd8e56c0 CR3: 000000000df38000 CR4: 00000000003526f0 Call Trace: skb_clone+0x1b2/0x3a0 net/core/skbuff.c:2040 deliver_clone net/bridge/br_forward.c:125 [inline] br_flood+0x414/0x6a0 net/bridge/br_forward.c:249 br_handle_frame_finish+0x14b4/0x19b0 net/bridge/br_input.c:221 br_nf_hook_thresh+0x3c3/0x4a0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0x948/0xd00 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x37e/0x6b0 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:283 [inline] br_handle_frame+0x982/0x14c0 net/bridge/br_input.c:434 __netif_receive_skb_core+0x10b6/0x4020 net/core/dev.c:5866 __netif_receive_skb_one_core net/core/dev.c:5977 [inline] __netif_receive_skb+0x72/0x380 net/core/dev.c:6092 process_backlog+0x60e/0x14f0 net/core/dev.c:6444 __napi_poll+0xc4/0x360 net/core/dev.c:7497 napi_poll net/core/dev.c:7560 [inline] net_rx_action+0x707/0xe30 net/core/dev.c:7687 handle_softirqs+0x283/0x870 kernel/softirq.c:579 do_softirq+0xec/0x180 kernel/softirq.c:480 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407 spin_unlock_bh include/linux/spinlock.h:396 [inline] cfg80211_inform_single_bss_data+0x13d2/0x1ac0 net/wireless/scan.c:2395 cfg80211_inform_bss_data+0x1fb/0x3b30 net/wireless/scan.c:3234 cfg80211_inform_bss_frame_data+0x3d7/0x730 net/wireless/scan.c:3325 ieee80211_bss_info_update+0x746/0x9e0 net/mac80211/scan.c:226 ieee80211_rx_bss_info net/mac80211/ibss.c:1094 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1573 [inline] ieee80211_ibss_rx_queued_mgmt+0xa36/0x2ae0 net/mac80211/ibss.c:1600 ieee80211_iface_process_skb net/mac80211/iface.c:1699 [inline] ieee80211_iface_work+0x85f/0x12d0 net/mac80211/iface.c:1753 cfg80211_wiphy_work+0x2df/0x460 net/wireless/core.c:435 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 net_ratelimit: 5556 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:0e:de:5c:98:2b:b8, 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: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:0c, 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:0e:de:5c:98:2b:b8, 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:aa:aa:aa:aa:aa:0c, vlan:0) net_ratelimit: 7058 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:0e:de:5c:98:2b:b8, 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: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:0c, 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:0e:de:5c:98:2b:b8, 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:aa:aa:aa:aa:aa:0c, vlan:0)