GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12875/1:b..l rcu: (detected by 1, t=10502 jiffies, g=65573, q=292 ncpus=2) task:syz.2.2283 state:R running task stack:25352 pid:12875 tgid:12874 ppid:5617 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x1b2a/0x59a0 kernel/sched/core.c:7232 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7554 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x910 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:__rcu_read_lock+0x31/0x60 kernel/rcu/tree_plugin.h:416 Code: 8b 1d db 6c c4 11 48 81 c3 c4 04 00 00 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 18 ff 03 8b 03 <3d> 00 00 00 40 7d 07 5b e9 42 64 31 0a cc 90 0f 0b 90 eb f3 89 d9 RSP: 0018:ffffc9000d5571b0 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffff88805a046284 RCX: dffffc0000000000 RDX: dffffc0000000000 RSI: ffffffff825176d9 RDI: ffffc9000d5572a0 RBP: 1ffff92001aaae54 R08: ffffc9000d557330 R09: 0000000000000005 R10: ffffc9000d5572b8 R11: ffffffff81b243c0 R12: dffffc0000000000 R13: ffffc9000d557d30 R14: ffffc9000d557268 R15: 1ffff92001aaae4d rcu_read_lock include/linux/rcupdate.h:847 [inline] class_rcu_constructor include/linux/rcupdate.h:1216 [inline] unwind_next_frame+0x88/0x2550 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:183 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:338 reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] free_unref_folios+0xdc2/0x14e0 mm/page_alloc.c:3080 folios_put_refs+0x9e9/0xb30 mm/folio.c:1034 folio_batch_release include/linux/folio_batch.h:101 [inline] shmem_undo_range+0x4e6/0x15d0 mm/shmem.c:1160 shmem_truncate_range mm/shmem.c:1288 [inline] shmem_evict_inode+0x247/0xae0 mm/shmem.c:1419 evict+0x624/0xb50 fs/inode.c:822 dentry_kill+0x1b9/0x880 fs/dcache.c:826 finish_dput+0x1a/0x260 fs/dcache.c:1001 __fput+0x675/0xa50 fs/file_table.c:520 fput_close_sync+0x11f/0x240 fs/file_table.c:617 __do_sys_close fs/open.c:1560 [inline] __se_sys_close fs/open.c:1545 [inline] __x64_sys_close+0x7e/0x110 fs/open.c:1545 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x510 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faaf8b5e90e RSP: 002b:00007faaf9a3ada8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 00007faaf9a3b6c0 RCX: 00007faaf8b5e90e RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 00007faaf9a3aee0 R14: 00007faaf9a3aea0 R15: 00007faaee800000 rcu: rcu_preempt kthread starved for 10495 jiffies! g65573 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:27496 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x1b2a/0x59a0 kernel/sched/core.c:7232 __schedule_loop kernel/sched/core.c:7309 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7324 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2122 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2330 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: CPU: 1 UID: 0 PID: 6938 Comm: kworker/u8:25 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:363 [inline] RIP: 0010:csd_lock kernel/smp.c:396 [inline] RIP: 0010:smp_call_function_many_cond+0x61c/0x1500 kernel/smp.c:944 Code: b6 04 04 84 c0 0f 85 d5 03 00 00 44 8b 3b 44 89 fe 83 e6 01 31 ff e8 a3 50 0c 00 41 83 e7 01 75 07 e8 58 4c 0c 00 eb 3f f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 04 04 84 c0 75 0f f7 03 01 RSP: 0018:ffffc900037bf720 EFLAGS: 00000293 RAX: ffffffff81bb38cc RBX: ffff8880b8643c88 RCX: ffff888035a51f40 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900037bf870 R08: ffff888035a534df R09: 1ffff11006b4a69b R10: dffffc0000000000 R11: 0000000000000000 R12: 1ffff110170c8791 R13: 0000000000000000 R14: ffff8880b8643c80 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff88812500c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f58f95eb7c0 CR3: 000000000e948000 CR4: 00000000003526f0 Call Trace: on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2602 [inline] smp_text_poke_batch_finish+0x5fd/0x1110 arch/x86/kernel/alternative.c:2812 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:902 process_one_work kernel/workqueue.c:3375 [inline] process_scheduled_works+0xc4e/0x1630 kernel/workqueue.c:3458 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3539 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