rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8017/3:b..l
rcu: (detected by 1, t=10502 jiffies, g=20025, q=748245 ncpus=2)
task:syz.3.546 state:R running task stack:26952 pid:8017 tgid:7999 ppid:5804 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7095
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__local_bh_enable_ip+0xff/0x120 kernel/softirq.c:457
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_read_unlock_bh include/linux/rcupdate.h:924 [inline]
__dev_queue_xmit+0x8b5/0x4800 net/core/dev.c:4873
dev_queue_xmit include/linux/netdevice.h:3385 [inline]
neigh_hh_output include/net/neighbour.h:540 [inline]
neigh_output include/net/neighbour.h:554 [inline]
ip_finish_output2+0xf4a/0x24d0 net/ipv4/ip_output.c:237
__ip_finish_output.part.0+0x444/0x6f0 net/ipv4/ip_output.c:315
__ip_finish_output net/ipv4/ip_output.c:303 [inline]
ip_finish_output net/ipv4/ip_output.c:325 [inline]
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip_output+0x39b/0xc10 net/ipv4/ip_output.c:438
dst_output include/net/dst.h:470 [inline]
ip_local_out+0x193/0x1f0 net/ipv4/ip_output.c:131
__ip_queue_xmit+0x885/0x1e90 net/ipv4/ip_output.c:534
__tcp_transmit_skb+0x3347/0x4b50 net/ipv4/tcp_output.c:1693
tcp_transmit_skb net/ipv4/tcp_output.c:1711 [inline]
tcp_send_syn_data net/ipv4/tcp_output.c:4287 [inline]
tcp_connect+0x2956/0x5630 net/ipv4/tcp_output.c:4376
tcp_v4_connect+0x1603/0x1b40 net/ipv4/tcp_ipv4.c:346
__inet_stream_connect+0x208/0xfa0 net/ipv4/af_inet.c:685
tcp_sendmsg_fastopen+0x3ed/0x750 net/ipv4/tcp.c:1099
tcp_sendmsg_locked+0x2791/0x45e0 net/ipv4/tcp.c:1195
tcp_sendmsg+0x2e/0x50 net/ipv4/tcp.c:1465
inet_sendmsg+0xb9/0x140 net/ipv4/af_inet.c:865
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
__sys_sendto+0x446/0x4b0 net/socket.c:2206
__do_sys_sendto net/socket.c:2213 [inline]
__se_sys_sendto net/socket.c:2209 [inline]
__x64_sys_sendto+0xe0/0x1c0 net/socket.c:2209
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8b89d9c799
RSP: 002b:00007f8b8ac41028 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f8b8a016180 RCX: 00007f8b89d9c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00007f8b89e32c99 R08: 0000200000000040 R09: 0000000000000010
R10: 0000000028040041 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8b8a016218 R14: 00007f8b8a016180 R15: 00007ffc9fb32008
rcu: rcu_preempt kthread starved for 731 jiffies! g20025 f0x2 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:27832 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7008
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x754/0xd80 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 8007 Comm: syz.2.550 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:unwind_next_frame+0x11da/0x1ea0 arch/x86/kernel/unwind_orc.c:532
Code: ff e9 96 f1 ff ff 80 3d c4 da 09 0f 00 0f 85 85 f1 ff ff e9 a0 e0 68 ff 48 b8 00 00 00 00 00 fc ff df 48 8b 14 24 48 c1 ea 03 <80> 3c 02 00 0f 85 02 09 00 00 48 89 c8 4d 8b 7d 38 48 ba 00 00 00
RSP: 0018:ffffc90000007158 EFLAGS: 00000a02
RAX: dffffc0000000000 RBX: 0000000000000002 RCX: ffffffff9208e7a2
RDX: 1ffff92000000e40 RSI: 0000000000000001 RDI: ffffffff91520dc8
RBP: ffffc90000007210 R08: ffffffff9208e7a6 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000085b8a R12: ffffc90000007218
R13: ffffc900000071c8 R14: 0000000000000005 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88812433f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000404030 CR3: 000000000e598000 CR4: 00000000003526f0
Call Trace:
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2685 [inline]
slab_free mm/slub.c:6165 [inline]
kmem_cache_free+0x124/0x6a0 mm/slub.c:6295
kfree_skbmem+0x19a/0x210 net/core/skbuff.c:1151
__kfree_skb net/core/skbuff.c:1218 [inline]
consume_skb net/core/skbuff.c:1450 [inline]
consume_skb+0xd1/0x110 net/core/skbuff.c:1444
nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:61 [inline]
nft_synproxy_do_eval+0xa7b/0xd50 net/netfilter/nft_synproxy.c:142
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x2e8/0x1930 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0xee/0x340 net/netfilter/nft_chain_filter.c:161
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xbf/0x220 net/netfilter/core.c:623
nf_hook.constprop.0+0x2a6/0x750 include/linux/netfilter.h:273
NF_HOOK include/linux/netfilter.h:316 [inline]
ip_local_deliver+0x163/0x1f0 net/ipv4/ip_input.c:262
dst_input include/net/dst.h:480 [inline]
ip_rcv_finish net/ipv4/ip_input.c:453 [inline]
NF_HOOK include/linux/netfilter.h:318 [inline]
NF_HOOK include/linux/netfilter.h:312 [inline]
ip_rcv+0x33a/0x3c0 net/ipv4/ip_input.c:573
__netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:6164
__netif_receive_skb+0x1f/0x120 net/core/dev.c:6277
process_backlog+0x37a/0x1580 net/core/dev.c:6628
__napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7692
napi_poll net/core/dev.c:7755 [inline]
net_rx_action+0xa40/0xf20 net/core/dev.c:7912
handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xef/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+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x5a2/0x1500 kernel/smp.c:877
Code: e4 63 0c 00 f3 90 41 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 91 0d 00 00 8b 45 08 31 ff 83 e0 01 41 89 c6 89 c6 e8 6e 5e 0c 00 <45> 85 f6 75 d0 e8 b4 63 0c 00 e8 af 63 0c 00 83 c3 01 bf 07 00 00
RSP: 0018:ffffc90003537288 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81fc7c42
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff8880203d0000
RBP: ffff8880b8540da0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170a81b5 R14: 0000000000000001 R15: ffff8880b843c440
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:57 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
flush_tlb_mm_range+0x45f/0x1710 arch/x86/mm/tlb.c:1472
flush_tlb_batched_pending+0x93/0xe0 mm/rmap.c:810
zap_pte_range mm/memory.c:1919 [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+0xb9f/0x4840 mm/memory.c:2091
unmap_single_vma+0x153/0x240 mm/memory.c:2133
unmap_vmas+0x295/0x590 mm/memory.c:2171
exit_mmap+0x1ef/0xa30 mm/mmap.c:1302
__mmput+0x12a/0x410 kernel/fork.c:1175
mmput+0x67/0x80 kernel/fork.c:1198
exit_mm kernel/exit.c:581 [inline]
do_exit+0x819/0x2b60 kernel/exit.c:964
do_group_exit+0xd5/0x2a0 kernel/exit.c:1118
get_signal+0x1ec7/0x21e0 kernel/signal.c:3034
arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x86/0x4a0 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+0x67c/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f80cdf9c799
Code: Unable to access opcode bytes at 0x7f80cdf9c76f.
RSP: 002b:00007f80cc1f6028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007f80ce216090 RCX: 00007f80cdf9c799
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007f80ce032c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f80ce216128 R14: 00007f80ce216090 R15: 00007ffebb7cfe38