rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11883/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=53581, q=650345 ncpus=2)
task:syz.2.1076 state:R running task stack:23496 pid:11883 tgid:11883 ppid:8554 task_flags:0x400040 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5313 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6696
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6876
preempt_schedule+0xae/0xc0 kernel/sched/core.c:6900
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__local_bh_enable_ip+0x13e/0x1c0 kernel/softirq.c:414
spin_unlock_bh include/linux/spinlock.h:396 [inline]
cfg80211_mlme_unregister_socket+0x2ce/0x690 net/wireless/mlme.c:761
nl80211_netlink_notify+0x356/0x840 net/wireless/nl80211.c:20816
notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85
blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380
netlink_release+0x1259/0x1b10 net/netlink/af_netlink.c:764
__sock_release net/socket.c:649 [inline]
sock_close+0xc0/0x240 net/socket.c:1439
__fput+0x44c/0xa70 fs/file_table.c:468
task_work_run+0x1d1/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:208 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7c6918e929
RSP: 002b:00007ffc5d957668 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f7c693b7ba0 RCX: 00007f7c6918e929
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f7c693b7ba0 R08: 00000000000019d0 R09: 0000001b5d95795f
R10: 00007f7c693b7ac0 R11: 0000000000000246 R12: 0000000000077d74
R13: 00007f7c693b6160 R14: ffffffffffffffff R15: 00007ffc5d957780
rcu: rcu_preempt kthread starved for 2119 jiffies! g53581 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:26792 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5313 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6696
__schedule_loop kernel/sched/core.c:6774 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6789
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2060
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2262
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
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: 0 Comm: swapper/1 Not tainted 6.16.0-rc4-next-20250702-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:751
Code: 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 53 65 ff 05 b0 a3 f9 10 e8 ab ec c8 09 <89> c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd b0
RSP: 0018:ffffc90000a07258 EFLAGS: 00000286
RAX: 0000000000000001 RBX: ffffffff90b74401 RCX: fe44f4f663ecfa00
RDX: ffffc90000a07301 RSI: ffffffff8be326a0 RDI: ffffffff8be32660
RBP: dffffc0000000000 R08: ffffc90000a07f70 R09: 0000000000000000
R10: ffffc90000a07398 R11: fffff52000140e75 R12: ffffc90000a07f80
R13: ffffc90000a01000 R14: ffffc90000a07348 R15: ffffffff81728c65
FS: 0000000000000000(0000) GS:ffff888125d1d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6323c00218 CR3: 000000003295a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000097 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
rcu_read_unlock include/linux/rcupdate.h:869 [inline]
class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0x1965/0x2390 arch/x86/kernel/unwind_orc.c:680
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2417 [inline]
slab_free mm/slub.c:4680 [inline]
kmem_cache_free+0x18f/0x400 mm/slub.c:4782
skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1087
skb_release_all net/core/skbuff.c:1152 [inline]
__kfree_skb net/core/skbuff.c:1166 [inline]
sk_skb_reason_drop+0x127/0x170 net/core/skbuff.c:1204
kfree_skb_reason include/linux/skbuff.h:1275 [inline]
enqueue_to_backlog+0xbc/0xfa0 net/core/dev.c:5191
netif_rx_internal+0x130/0x560 net/core/dev.c:5489
__netif_rx+0x78/0xc0 net/core/dev.c:5509
loopback_xmit+0x47a/0x6f0 drivers/net/loopback.c:90
__netdev_start_xmit include/linux/netdevice.h:5217 [inline]
netdev_start_xmit include/linux/netdevice.h:5226 [inline]
xmit_one net/core/dev.c:3828 [inline]
dev_hard_start_xmit+0x2d4/0x830 net/core/dev.c:3844
sch_direct_xmit+0x241/0x4b0 net/sched/sch_generic.c:344
qdisc_restart net/sched/sch_generic.c:409 [inline]
__qdisc_run+0xb16/0x15f0 net/sched/sch_generic.c:417
__dev_xmit_skb net/core/dev.c:4169 [inline]
__dev_queue_xmit+0xfe1/0x3a70 net/core/dev.c:4677
dev_queue_xmit include/linux/netdevice.h:3358 [inline]
neigh_hh_output include/net/neighbour.h:526 [inline]
neigh_output include/net/neighbour.h:540 [inline]
ip_finish_output2+0xd03/0x1160 net/ipv4/ip_output.c:235
synproxy_send_client_synack+0x8bb/0xe20 net/netfilter/nf_synproxy_core.c:484
nft_synproxy_eval_v4+0x36e/0x560 net/netfilter/nft_synproxy.c:59
nft_synproxy_do_eval+0x345/0x570 net/netfilter/nft_synproxy.c:141
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x40c/0x1920 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x25d/0x340 net/netfilter/nft_chain_filter.c:161
nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline]
nf_hook_slow+0xc2/0x220 net/netfilter/core.c:623
nf_hook include/linux/netfilter.h:272 [inline]
NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:315
NF_HOOK+0x309/0x3a0 include/linux/netfilter.h:317
__netif_receive_skb_one_core net/core/dev.c:5975 [inline]
__netif_receive_skb+0x143/0x380 net/core/dev.c:6088
process_backlog+0x60e/0x14f0 net/core/dev.c:6440
__napi_poll+0xc7/0x480 net/core/dev.c:7453
napi_poll net/core/dev.c:7517 [inline]
net_rx_action+0x707/0xe30 net/core/dev.c:7644
handle_softirqs+0x286/0x870 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 83 dd 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 e3 c2 18 00 f3 0f 1e fa fb f4 58 dd 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: fe44f4f663ecfa00 RBX: ffffffff8196c188 RCX: fe44f4f663ecfa00
RDX: 0000000000000001 RSI: ffffffff8d993fd3 RDI: ffffffff8be326c0
RBP: ffffc90000197f20 R08: ffff8880b8732f1b R09: 1ffff110170e65e3
R10: dffffc0000000000 R11: ffffed10170e65e4 R12: ffffffff8fa17c30
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003a57b40
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:757
default_idle_call+0x74/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x1e8/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x147