rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13992/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=92857, q=1692 ncpus=2)
task:syz.5.2102 state:R running task stack:26024 pid:13992 tgid:13984 ppid:8909 task_flags:0x40054c flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6911
preempt_schedule_notrace+0x57/0x90 kernel/sched/core.c:7188
preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:753
rcu_read_lock include/linux/rcupdate.h:851 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0xd4/0x23c0 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:1433 [inline]
free_unref_folios+0xed5/0x16d0 mm/page_alloc.c:3040
folios_put_refs+0x789/0x8d0 mm/swap.c:1002
free_pages_and_swap_cache+0x2e7/0x5b0 mm/swap_state.c:423
__tlb_batch_free_encoded_pages mm/mmu_gather.c:138 [inline]
tlb_batch_pages_flush mm/mmu_gather.c:151 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:398 [inline]
tlb_flush_mmu+0x6d3/0xa30 mm/mmu_gather.c:405
zap_pte_range mm/memory.c:1968 [inline]
zap_pmd_range mm/memory.c:2021 [inline]
zap_pud_range mm/memory.c:2049 [inline]
zap_p4d_range mm/memory.c:2070 [inline]
unmap_page_range+0x3c1d/0x48f0 mm/memory.c:2091
unmap_single_vma mm/memory.c:2133 [inline]
unmap_vmas+0x48f/0x6a0 mm/memory.c:2171
exit_mmap+0x280/0xa10 mm/mmap.c:1302
__mmput+0x118/0x430 kernel/fork.c:1175
exit_mm+0x168/0x220 kernel/exit.c:581
do_exit+0x6a2/0x23c0 kernel/exit.c:964
do_group_exit+0x21b/0x2d0 kernel/exit.c:1118
get_signal+0x1284/0x1330 kernel/signal.c:3034
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:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1668d9c799
RSP: 002b:00007f1666b89028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: 0000000000000006 RBX: 00007f1669016270 RCX: 00007f1668d9c799
RDX: 0000000000000006 RSI: 0000200000000040 RDI: 0000000000000008
RBP: 00007f1668e32c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1669016308 R14: 00007f1669016270 R15: 00007f166913fa48
rcu: rcu_preempt kthread starved for 414 jiffies! g92857 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:27696 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7008
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+0x51e/0xb90 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: 5944 Comm: ipvs-e:1:0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:user_mode arch/x86/include/asm/ptrace.h:214 [inline]
RIP: 0010:unwind_next_frame+0x14c/0x23c0 arch/x86/kernel/unwind_orc.c:498
Code: 38 80 3c 28 00 74 08 4c 89 ef e8 0f 64 b9 00 49 8b 5d 00 48 85 db 74 23 48 81 c3 88 00 00 00 48 89 d8 48 c1 e8 03 0f b6 04 28 <84> c0 0f 85 4e 1b 00 00 f6 03 03 0f 85 e5 18 00 00 49 8d 5e 35 48
RSP: 0018:ffffc90000a07d98 EFLAGS: 00000a06
RAX: 0000000000000000 RBX: ffffc90004577770 RCX: 0000000080000102
RDX: 00000000a42637f2 RSI: ffffffff8c27c1e0 RDI: ffffffff8c27c1a0
RBP: dffffc0000000000 R08: ffffffff81767e95 R09: ffffffff8e75e520
R10: ffffc90000a07eb8 R11: ffffffff81b0c260 R12: 1ffff92000140fcd
R13: ffffc90000a07eb8 R14: ffffc90000a07e68 R15: ffffffff81767e95
FS: 0000000000000000(0000) GS:ffff88812555d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdc3dc00218 CR3: 000000007d85c000 CR4: 00000000003526f0
Call Trace:
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:4538 [inline]
slab_alloc_node mm/slub.c:4866 [inline]
kmem_cache_alloc_node_noprof+0x384/0x690 mm/slub.c:4918
__alloc_skb+0x1d0/0x7d0 net/core/skbuff.c:702
alloc_skb include/linux/skbuff.h:1383 [inline]
synproxy_send_client_synack+0x172/0xe30 net/netfilter/nf_synproxy_core.c:461
nft_synproxy_eval_v4+0x34a/0x4e0 net/netfilter/nft_synproxy.c:60
nft_synproxy_do_eval+0x305/0x580 net/netfilter/nft_synproxy.c:142
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x45e/0x1990 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x29d/0x380 net/netfilter/nft_chain_filter.c:161
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6164 [inline]
__netif_receive_skb net/core/dev.c:6277 [inline]
process_backlog+0xaa3/0x1950 net/core/dev.c:6628
__napi_poll+0xae/0x340 net/core/dev.c:7692
napi_poll net/core/dev.c:7755 [inline]
net_rx_action+0x627/0xf70 net/core/dev.c:7912
handle_softirqs+0x22a/0x870 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:finish_task_switch+0x245/0x920 kernel/sched/core.c:5155
Code: 00 00 48 85 db 0f 85 e8 01 00 00 e9 56 05 00 00 4c 8b 75 d0 49 83 c4 48 4c 89 e7 e8 05 07 1c 0a e8 80 7f 38 00 fb 4c 8b 65 c0 <49> 8d bc 24 80 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc90004577798 EFLAGS: 00000206
RAX: 000000000004bc09 RBX: 0000000000000000 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8def7890 RDI: ffffffff8c27c200
RBP: ffffc900045777f0 R08: ffffffff9011a3b7 R09: 1ffffffff2023476
R10: dffffc0000000000 R11: fffffbfff2023477 R12: ffff888028591e80
R13: dffffc0000000000 R14: ffff888025de9e80 R15: ffff8880b873b918
context_switch kernel/sched/core.c:5301 [inline]
__schedule+0x15e5/0x52d0 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7008
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
ip_vs_estimation_kthread+0x2ae7/0x3a80 net/netfilter/ipvs/ip_vs_est.c:208
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245