GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P14071/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=62873, q=895 ncpus=2)
task:syz.1.2193 state:R running task stack:25016 pid:14071 tgid:14056 ppid:5631 task_flags:0x40044c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x760 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:_static_cpu_has arch/x86/include/asm/cpufeature.h:101 [inline]
RIP: 0010:__nr_to_section include/linux/mmzone.h:2061 [inline]
RIP: 0010:__pfn_to_section include/linux/mmzone.h:2198 [inline]
RIP: 0010:lookup_page_ext mm/page_ext.c:255 [inline]
RIP: 0010:page_ext_lookup+0x165/0x180 mm/page_ext.c:513
Code: 5e 41 5f 5d c3 cc cc cc cc cc e8 06 3d 89 ff e9 73 ff ff ff e8 fc 3c 89 ff 90 0f 0b 90 eb a1 e8 f1 3c 89 ff 41 bf 00 10 00 00 ce fe ff ff e8 e1 3c 89 ff e9 be fe ff ff 66 66 66 2e 0f 1f 84
RSP: 0018:ffffc9001c4befd8 EFLAGS: 00000293
RAX: ffffffff823c87cf RBX: 000000000006b4f3 RCX: ffff888050861ec0
RDX: 0000000000000000 RSI: ffffffff8c28b640 RDI: 000000000006b4f3
RBP: dffffc0000000000 R08: ffffffff823c912a R09: ffffffff8e95cca0
R10: dffffc0000000000 R11: ffffed10067eb128 R12: 000000000006b4f3
R13: 000000000006b4f3 R14: 0000000000000000 R15: 0000000000001000
page_ext_iter_begin include/linux/page_ext.h:133 [inline]
__page_table_check_zero+0x135/0x3e0 mm/page_table_check.c:139
page_table_check_free include/linux/page_table_check.h:46 [inline]
__free_pages_prepare mm/page_alloc.c:1403 [inline]
free_unref_folios+0xcfb/0x1480 mm/page_alloc.c:3004
folios_put_refs+0x9ff/0xb40 mm/swap.c:1008
folio_batch_release include/linux/folio_batch.h:101 [inline]
shmem_undo_range+0x52c/0x1660 mm/shmem.c:1149
shmem_truncate_range mm/shmem.c:1277 [inline]
shmem_evict_inode+0x289/0xae0 mm/shmem.c:1407
evict+0x61e/0xb10 fs/inode.c:841
__dentry_kill+0x1a2/0x690 fs/dcache.c:718
finish_dput+0xc9/0x480 fs/dcache.c:927
__fput+0x691/0xa60 fs/file_table.c:518
task_work_run+0x1d9/0x270 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x70f/0x22c0 kernel/exit.c:976
do_group_exit+0x21b/0x2d0 kernel/exit.c:1119
get_signal+0x1284/0x1330 kernel/signal.c:3037
arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x8c/0x4d0 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
ret_from_fork+0x593/0xb70 arch/x86/kernel/process.c:167
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread starved for 2430 jiffies! g62873 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:27544 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
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+0x389/0x470 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: 0 UID: 0 PID: 10171 Comm: kworker/u8:55 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: bat_events batadv_dat_purge
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x35/0xb0 kernel/rcu/tree.c:752
Code: 05 20 b2 8e 11 e8 5b 82 fe 09 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 90 b7 26 8e 4c 89 f0 48 c1 e8 03 <42> 80 3c 38 00 74 08 4c 89 f7 e8 9c 26 86 00 48 c7 c3 d8 c9 3a 93
RSP: 0018:ffffc90000007028 EFLAGS: 00000a02
RAX: 1ffffffff1c4d6f2 RBX: 0000000000000000 RCX: 0000000080000102
RDX: ffff888079aa3d80 RSI: ffffffff8c28b640 RDI: ffffffff8c28b600
RBP: 000000000000004b R08: ffffffff8a85854e R09: ffffffff8e95cca0
R10: 0000000000000003 R11: ffffffff8a85b8b0 R12: dffffc0000000000
R13: ffff88809b866a00 R14: ffffffff8e26b790 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888125287000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc5087934ac CR3: 000000000e74a000 CR4: 00000000003526f0
Call Trace:
rcu_read_lock include/linux/rcupdate.h:839 [inline]
net_generic+0x59/0x240 include/net/netns/generic.h:45
is_vlan_ip net/bridge/br_netfilter_hooks.c:94 [inline]
br_nf_forward+0xd9/0x18d0 net/bridge/br_netfilter_hooks.c:773
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x23e/0x3f0 include/linux/netfilter.h:316
__br_forward+0x397/0x540 net/bridge/br_forward.c:115
deliver_clone net/bridge/br_forward.c:131 [inline]
maybe_deliver net/bridge/br_forward.c:191 [inline]
br_flood+0x6ee/0xb80 net/bridge/br_forward.c:238
br_handle_frame_finish+0x1521/0x1c80 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:6089
__netif_receive_skb_one_core net/core/dev.c:6200 [inline]
__netif_receive_skb net/core/dev.c:6315 [inline]
process_backlog+0x76d/0x1950 net/core/dev.c:6666
__napi_poll+0xae/0x340 net/core/dev.c:7733
napi_poll net/core/dev.c:7796 [inline]
net_rx_action+0x627/0xf70 net/core/dev.c:7953
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]
__batadv_dat_purge net/batman-adv/distributed-arp-table.c:185 [inline]
batadv_dat_purge+0x2da/0x3c0 net/batman-adv/distributed-arp-table.c:204
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
kthread+0x389/0x470 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