rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P29264/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=326009, q=1899 ncpus=2)
task:syz.9.6641 state:R running task stack:24408 pid:29264 tgid:29257 ppid:21651 task_flags:0x40054c flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x17b4/0x5680 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:547 [inline]
irqentry_exit+0x14f/0x730 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 51 94 06 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 3b 4f 97 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 48 4f 92
RSP: 0018:ffffc900055d7518 EFLAGS: 00000286
RAX: e02e18e06944a500 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 000000005a44979c RSI: ffffffff8e218c65 RDI: ffffffff8c28ade0
RBP: ffffffff8176f256 R08: ffffffff8176f256 R09: ffffffff8e95cd60
R10: ffffc900055d7678 R11: ffffffff81b0e910 R12: 0000000000000002
R13: ffffffff8e95cd60 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:838 [inline]
class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0xc3/0x2550 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: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:1402 [inline]
__free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943
vfree+0x1d1/0x2f0 mm/vmalloc.c:3472
kcov_put kernel/kcov.c:442 [inline]
kcov_close+0x28/0x50 kernel/kcov.c:543
__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:975
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:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f922219cdd9
RSP: 002b:00007f9222fba0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f9222416188 RCX: 00007f922219cdd9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f9222416188
RBP: 00007f9222416180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9222416218 R14: 00007f922253f960 R15: 00007f922253fa48
rcu: rcu_preempt kthread starved for 3406 jiffies! g326009 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:27544 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x17b4/0x5680 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+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: 10763 Comm: kworker/1:12 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: 0x0 (wg-crypt-wg1)
RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 51 94 06 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 3b 4f 97 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 48 4f 92
RSP: 0018:ffffc90000a07cd8 EFLAGS: 00000286
RAX: bd58be7b91ff3b00 RBX: 0000000000000000 RCX: 0000000080000101
RDX: 000000007f45ee1d RSI: ffffffff8e218c65 RDI: ffffffff8c28ade0
RBP: ffffffff8176f256 R08: ffffffff8176f256 R09: ffffffff8e95cd60
R10: ffffc90000a07e38 R11: ffffffff81b0e910 R12: 0000000000000002
R13: ffffffff8e95cd60 R14: 0000000000000000 R15: 0000000000000246
FS: 0000000000000000(0000) GS:ffff888125390000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000ed030 CR3: 000000000e74a000 CR4: 00000000003526f0
Call Trace:
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:838 [inline]
class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0xc3/0x2550 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
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_node_noprof+0x384/0x690 mm/slub.c:4950
__alloc_skb+0x1d0/0x7d0 net/core/skbuff.c:702
alloc_skb include/linux/skbuff.h:1383 [inline]
synproxy_send_client_synack_ipv6+0x16f/0xcb0 net/netfilter/nf_synproxy_core.c:874
nft_synproxy_eval_v6+0x34a/0x4e0 net/netfilter/nft_synproxy.c:91
nft_synproxy_do_eval+0x3ce/0x580 net/netfilter/nft_synproxy.c:146
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x467/0x19f0 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x360/0x4b0 net/netfilter/nft_chain_filter.c:162
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+0x21f/0x3c0 include/linux/netfilter.h:316
ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:540
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6202 [inline]
__netif_receive_skb net/core/dev.c:6315 [inline]
process_backlog+0x7dd/0x1950 net/core/dev.c:6666
__napi_poll+0xae/0x340 net/core/dev.c:7730
napi_poll net/core/dev.c:7793 [inline]
net_rx_action+0x627/0xf70 net/core/dev.c:7950
handle_softirqs+0x22a/0x840 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198
Code: f7 e8 ad 65 f7 f5 f7 c3 00 02 00 00 74 05 e8 b0 fb 22 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 24 e8 e8 f5 65 8b 05 ed 10 8e 07 85 c0 74 18 5b 41 5e e9 51 48
RSP: 0018:ffffc9000fff7930 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000282 RCX: 0000000080000001
RDX: 0000000000000007 RSI: ffffffff8dfa5c64 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffffffff9030a9f7 R09: 1ffffffff206153e
R10: dffffc0000000000 R11: fffffbfff206153f R12: ffff888065950000
R13: ffff88806594c000 R14: ffffffff9a690868 R15: 0000000000000002
__debug_check_no_obj_freed lib/debugobjects.c:1125 [inline]
debug_check_no_obj_freed+0x52e/0x550 lib/debugobjects.c:1146
__free_pages_prepare mm/page_alloc.c:1409 [inline]
__free_frozen_pages+0x593/0xd30 mm/page_alloc.c:2943
__slab_free+0x274/0x2c0 mm/slub.c:5612
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]
__kmalloc_cache_node_noprof+0x3ef/0x6b0 mm/slub.c:5431
kmalloc_node_noprof include/linux/slab.h:1077 [inline]
alloc_worker kernel/workqueue.c:2686 [inline]
create_worker+0x113/0x7e0 kernel/workqueue.c:2829
maybe_create_worker kernel/workqueue.c:3101 [inline]
manage_workers kernel/workqueue.c:3178 [inline]
worker_thread+0x4d8/0xfc0 kernel/workqueue.c:3441
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