rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P20303/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=160705, q=424593 ncpus=2)
task:syz.3.4458 state:R running task stack:25288 pid:20303 tgid:20302 ppid:16338 task_flags:0x40054c flags:0x08080003
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7370
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__local_bh_enable_ip+0xe1/0x130 kernel/softirq.c:457
nl80211_netlink_notify+0x46b/0x840 net/wireless/nl80211.c:22542
notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85
blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380
netlink_release+0x123b/0x1ad0 net/netlink/af_netlink.c:761
__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+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]
__do_fast_syscall_32+0x446/0x6e0 arch/x86/entry/syscall_32.c:310
do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f6901c
RSP: 002b:00000000f542650c EFLAGS: 00000206 ORIG_RAX: 0000000000000151
RAX: 0000000000010106 RBX: 0000000000000007 RCX: 00000000800000c0
RDX: 0000000000010106 RSI: 0000000000000002 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 754 jiffies! g160705 f0x2 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+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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:58 [inline]
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:409 [inline]
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:419 [inline]
RIP: 0010:unwind_next_frame+0xdf2/0x2550 arch/x86/kernel/unwind_orc.c:614
Code: 00 fc ff df 48 8b 4c 24 20 0f b6 04 01 84 c0 0f 85 2c 12 00 00 41 83 3e 00 0f 95 c0 49 39 df 0f 96 c1 20 c1 49 39 dc 0f 97 c0 <20> c8 3c 01 75 18 48 8d 43 08 4c 39 f8 0f 97 c1 4c 39 e0 0f 96 c0
RSP: 0018:ffffc90000a07e38 EFLAGS: 00000216
RAX: 0000000000000001 RBX: ffffc90000a08818 RCX: 1ffff92000140f01
RDX: ffffffff9151288c RSI: 0000000000000002 RDI: ffffffff8c28b780
RBP: 1ffff92000140fe2 R08: 0000000000000001 R09: ffffffff8e95cca0
R10: ffffc90000a07f58 R11: ffffffff81b0e040 R12: ffffc90000a09000
R13: 1ffff92000140fe3 R14: ffffc90000a07f08 R15: ffffc90000a01000
FS: 0000000000000000(0000) GS:ffff888125387000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005620fff9a088 CR3: 0000000065084000 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
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]
kfree+0x1c5/0x640 mm/slub.c:6566
skb_kfree_head net/core/skbuff.c:1075 [inline]
skb_free_head net/core/skbuff.c:1087 [inline]
skb_release_data+0x828/0xa60 net/core/skbuff.c:1114
skb_release_all net/core/skbuff.c:1189 [inline]
__kfree_skb+0x5d/0x210 net/core/skbuff.c:1203
nft_synproxy_eval_v4+0x352/0x4e0 net/netfilter/nft_synproxy.c:61
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+0x48d/0x1ae0 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
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+0xaa3/0x1950 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 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:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: 6b 7d 02 e9 93 f7 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d f3 01 20 00 fb f4 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffc90000197e20 EFLAGS: 00000242
RAX: 00000000012eaee3 RBX: ffffffff819a858a RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8dfad387 RDI: ffffffff8c28b7e0
RBP: ffffc90000197f10 R08: ffff8880b87339db R09: 1ffff110170e673b
R10: dffffc0000000000 R11: ffffed10170e673c R12: 0000000000000001
R13: 1ffff11003b5b000 R14: 0000000000000001 R15: 1ffff11003b5b000
arch_safe_halt arch/x86/kernel/process.c:766 [inline]
default_idle+0x9/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x36a/0x5f0 kernel/sched/idle.c:352
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147