rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P18679/1:b..l P21234/1:b..l rcu: (detected by 0, t=10503 jiffies, g=183653, q=919 ncpus=2) task:syz.7.4190 state:R running task stack:26872 pid:21234 tgid:21234 ppid:18425 task_flags:0x40044c flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5354 [inline] __schedule+0x165c/0x5520 kernel/sched/core.c:6966 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7294 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:stack_access_ok arch/x86/kernel/unwind_orc.c:409 [inline] RIP: 0010:deref_stack_reg+0xc9/0x230 arch/x86/kernel/unwind_orc.c:419 Code: 83 3f 00 0f 95 c0 4c 39 c3 0f 96 c1 20 c1 4d 39 c6 0f 97 c0 20 c8 3c 01 75 18 49 8d 40 08 48 39 d8 0f 97 c1 4c 39 f0 0f 96 c0 <84> c1 0f 85 c3 00 00 00 49 8d 7f 28 48 89 f8 48 c1 e8 03 80 3c 30 RSP: 0018:ffffc90006e9f060 EFLAGS: 00000287 RAX: ffffc90006e9fe01 RBX: ffffc90006e98000 RCX: 0000000000000001 RDX: ffffc90006e9f1c8 RSI: dffffc0000000000 RDI: ffffc90006e9f188 RBP: 1ffff92000dd3e31 R08: ffffc90006e9fee0 R09: 0000000000000000 R10: ffffc90006e9f1d8 R11: fffff52000dd3e3d R12: 1ffff92000dd3e32 R13: 1ffff92000dd3e33 R14: ffffc90006ea0000 R15: ffffc90006e9f188 unwind_next_frame+0x19d5/0x2550 arch/x86/kernel/unwind_orc.c:-1 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3131 [inline] call_rcu+0xee/0x890 kernel/rcu/tree.c:3251 slab_free_hook mm/slub.c:2653 [inline] slab_free mm/slub.c:6242 [inline] kmem_cache_free+0x462/0x650 mm/slub.c:6369 anon_vma_free mm/rmap.c:137 [inline] __put_anon_vma+0x12b/0x2d0 mm/rmap.c:2915 put_anon_vma mm/internal.h:216 [inline] unlink_anon_vmas+0x58b/0x730 mm/rmap.c:536 free_pgtables+0x836/0xb70 mm/memory.c:414 exit_mmap+0x490/0x9e0 mm/mmap.c:1312 __mmput+0x118/0x430 kernel/fork.c:1178 exit_mm+0x18e/0x250 kernel/exit.c:581 do_exit+0x6a2/0x22c0 kernel/exit.c:963 do_group_exit+0x21b/0x2d0 kernel/exit.c:1117 get_signal+0x1284/0x1330 kernel/signal.c:3037 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc402f5d04e RSP: 002b:00007fc403e15f58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007fc403e166c0 RCX: 00007fc402f5d04e RDX: 00007fc403e15fb0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fc403032c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc403216038 R14: 00007fc403215fa0 R15: 00007ffc306eedf8 task:syz.7.3423 state:R running task stack:26872 pid:18679 tgid:18679 ppid:18425 task_flags:0x40044c flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5354 [inline] __schedule+0x165c/0x5520 kernel/sched/core.c:6966 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7151 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:190 spin_unlock include/linux/spinlock.h:390 [inline] zap_pte_range mm/memory.c:1948 [inline] zap_pmd_range mm/memory.c:2004 [inline] zap_pud_range mm/memory.c:2032 [inline] zap_p4d_range mm/memory.c:2053 [inline] __zap_vma_range+0x3d17/0x4b40 mm/memory.c:2093 unmap_vmas+0x379/0x530 mm/memory.c:2162 exit_mmap+0x280/0x9e0 mm/mmap.c:1300 __mmput+0x118/0x430 kernel/fork.c:1178 exit_mm+0x18e/0x250 kernel/exit.c:581 do_exit+0x6a2/0x22c0 kernel/exit.c:963 do_group_exit+0x21b/0x2d0 kernel/exit.c:1117 get_signal+0x1284/0x1330 kernel/signal.c:3037 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc402f5d04e RSP: 002b:00007fc403e15f58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007fc403e166c0 RCX: 00007fc402f5d04e RDX: 00007fc403e15fb0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fc403032c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc403216038 R14: 00007fc403215fa0 R15: 00007ffc306eedf8 rcu: rcu_preempt kthread starved for 671 jiffies! g183653 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27528 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5354 [inline] __schedule+0x165c/0x5520 kernel/sched/core.c:6966 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7151 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] _raw_spin_unlock_irqrestore+0x74/0x80 kernel/locking/spinlock.c:198 prepare_to_swait_event+0x340/0x370 kernel/sched/swait.c:120 rcu_gp_fqs_loop+0x2dd/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+0x514/0xb70 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 17688 Comm: kworker/u8:14 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline] RIP: 0010:lock_release+0x266/0x3c0 kernel/locking/lockdep.c:5891 Code: 89 f6 48 8b 54 24 18 e8 28 2f 00 00 48 8b 5c 24 08 48 c7 c7 44 db 37 8e e8 37 ed 17 0a b8 ff ff ff ff 65 0f c1 05 7a 62 9f 11 <83> f8 01 75 2e 9c 58 a9 00 02 00 00 75 42 f7 c3 00 02 00 00 75 47 RSP: 0018:ffffc90000a07cf0 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000202 RCX: 0000000080000101 RDX: 0000000000000004 RSI: ffffffff8e37db44 RDI: ffffffff8c2a9260 RBP: ffff88801dbf0bf0 R08: ffffc90000a07f10 R09: 0000000000000000 R10: ffffc90000a07ed8 R11: fffff52000140fdd R12: 0000000000000004 R13: 0000000000000004 R14: ffffffff8e95d260 R15: ffff88801dbf0000 FS: 0000000000000000(0000) GS:ffff888125304000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000209030 CR3: 000000003031e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: rcu_lock_release include/linux/rcupdate.h:322 [inline] rcu_read_unlock include/linux/rcupdate.h:881 [inline] class_rcu_destructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0x1bba/0x2550 arch/x86/kernel/unwind_orc.c:709 __unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:787 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 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4905 skb_clone+0x212/0x3a0 net/core/skbuff.c:2109 deliver_clone net/bridge/br_forward.c:125 [inline] br_flood+0x8cf/0xb80 net/bridge/br_forward.c:250 br_handle_frame_finish+0x14c2/0x1bb0 net/bridge/br_input.c:229 br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0x91f/0xc30 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x374/0x6f0 net/bridge/br_netfilter_ipv6.c:183 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0x1277/0x1510 net/bridge/br_input.c:442 __netif_receive_skb_core+0x98f/0x3170 net/core/dev.c:6082 __netif_receive_skb_one_core net/core/dev.c:6193 [inline] __netif_receive_skb net/core/dev.c:6308 [inline] process_backlog+0x76d/0x1950 net/core/dev.c:6659 __napi_poll+0xae/0x340 net/core/dev.c:7723 napi_poll net/core/dev.c:7786 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7943 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] cfg80211_inform_single_bss_data+0x13b9/0x1af0 net/wireless/scan.c:2388 cfg80211_inform_bss_data+0x266/0x3c40 net/wireless/scan.c:3226 cfg80211_inform_bss_frame_data+0x3c7/0x730 net/wireless/scan.c:3317 ieee80211_bss_info_update+0x794/0xa40 net/mac80211/scan.c:230 ieee80211_rx_bss_info net/mac80211/ibss.c:1088 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1569 [inline] ieee80211_ibss_rx_queued_mgmt+0x1901/0x2cb0 net/mac80211/ibss.c:1596 ieee80211_iface_process_skb net/mac80211/iface.c:1757 [inline] ieee80211_iface_work+0x845/0x1380 net/mac80211/iface.c:1811 cfg80211_wiphy_work+0x2cf/0x460 net/wireless/core.c:513 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 net_ratelimit: 15633 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:62:ae:60:ed:89:9d, 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:62:ae:60:ed:89:9d, 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:62:ae:60:ed:89:9d, 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:62:ae:60:ed:89:9d, 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:62:ae:60:ed:89:9d, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)