rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P20699/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=104973, q=1726 ncpus=2)
task:syz.0.3925 state:R running task stack:25632 pid:20699 tgid:20695 ppid:18298 task_flags:0x40054c flags:0x00080003
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/0x8b0 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0x718/0x2550 arch/x86/kernel/unwind_orc.c:527
Code: 89 14 24 48 89 74 24 08 0f 85 9e 17 00 00 4c 89 e0 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 b5 17 00 00 0f b7 1e c1 eb 0b 80 e3 01 <48> 8b 44 24 38 0f b6 04 28 84 c0 0f 85 c4 17 00 00 48 8b 44 24 18
RSP: 0018:ffffc9000347f1d8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff90b81b5c
RDX: ffffffff916b84ba RSI: ffffffff916b84be RDI: ffffffff8c28b700
RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff8e95cce0
R10: ffffc9000347f2f8 R11: ffffffff81b0e210 R12: ffffffff916b84bf
R13: 1ffff9200068fe55 R14: ffffc9000347f2a8 R15: ffffffff8176e256
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
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:6251 [inline]
kmem_cache_free+0x182/0x650 mm/slub.c:6378
skb_ext_reset include/linux/skbuff.h:5118 [inline]
skb_release_head_state+0x270/0x360 net/core/skbuff.c:1181
skb_release_all net/core/skbuff.c:1187 [inline]
__kfree_skb+0x24/0x210 net/core/skbuff.c:1203
kfree_skb_reason include/linux/skbuff.h:1324 [inline]
__skb_queue_purge_reason include/linux/skbuff.h:3442 [inline]
skb_queue_purge_reason+0x2ee/0x3b0 net/core/skbuff.c:4018
skb_queue_purge include/linux/skbuff.h:3455 [inline]
packet_release+0xb65/0xd10 net/packet/af_packet.c:3184
__sock_release net/socket.c:722 [inline]
sock_close+0xc3/0x240 net/socket.c:1514
__fput+0x44f/0xa60 fs/file_table.c:510
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+0xa9/0x680 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]
do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8f4f99ce59
RSP: 002b:00007f8f50860028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: 000000000000005c RBX: 00007f8f4fc16090 RCX: 00007f8f4f99ce59
RDX: 0000000000000000 RSI: 0000200000000300 RDI: 0000000000000009
RBP: 00007f8f4fa32d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8f4fc16128 R14: 00007f8f4fc16090 R15: 00007fffb1d252d8
rcu: rcu_preempt kthread starved for 292 jiffies! g104973 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:27064 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: 8 Comm: kworker/R-netns Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: netns cleanup_net
RIP: 0010:unwind_get_return_address+0x45/0x90 arch/x86/kernel/unwind_orc.c:385
Code: e8 03 42 0f b6 04 30 84 c0 75 4c 83 3b 00 74 3a 48 83 c3 48 49 89 df 49 c1 ef 03 43 80 3c 37 00 74 08 48 89 df e8 2b 2d ba 00 <48> 8b 3b e8 a3 dc 18 00 85 c0 74 14 43 80 3c 37 00 74 08 48 89 df
RSP: 0018:ffffc900000d72a8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc900000d7310 RCX: 0000000000000046
RDX: 0000000000000005 RSI: ffffffff8e215ff1 RDI: ffffc900000d72c8
RBP: ffffc900000d7350 R08: ffffc900000d7a90 R09: 0000000000000000
R10: ffffc900000d7318 R11: fffff5200001ae65 R12: ffff88801d6e8000
R13: 1ffff11003add0be R14: dffffc0000000000 R15: 1ffff9200001ae62
FS: 0000000000000000(0000) GS:ffff88812529e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056132fd864b0 CR3: 00000000297b0000 CR4: 00000000003526f0
Call Trace:
arch_stack_walk+0xfb/0x150 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:165
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1397 [inline]
__free_frozen_pages+0xc1c/0xd30 mm/page_alloc.c:2938
__slab_free+0x274/0x2c0 mm/slub.c:5613
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_kmalloc+0x22/0xb0 mm/kasan/common.c:406
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5296 [inline]
__kvmalloc_node_noprof+0x528/0x8a0 mm/slub.c:6833
allocate_hook_entries_size net/netfilter/core.c:54 [inline]
__nf_hook_entries_try_shrink+0x328/0x700 net/netfilter/core.c:253
__nf_unregister_net_hook+0x4cc/0x6f0 net/netfilter/core.c:513
nf_unregister_net_hook net/netfilter/core.c:-1 [inline]
nf_unregister_net_hooks+0xcb/0x140 net/netfilter/core.c:606
ops_pre_exit_list net/core/net_namespace.c:161 [inline]
ops_undo_list+0x187/0x940 net/core/net_namespace.c:234
cleanup_net+0x56b/0x800 net/core/net_namespace.c:702
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
rescuer_thread+0x827/0x1130 kernel/workqueue.c:3621
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