rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6791
rcu: (detected by 0, t=10503 jiffies, g=17833, q=1263 ncpus=2)
task:syz.2.239 state:R running task stack:24536 pid:6791 tgid:6782 ppid:5846 task_flags:0x400040 flags:0x10080013
Call Trace:
sched_show_task+0x49d/0x630 kernel/sched/core.c:7901
rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:292 [inline]
print_other_cpu_stall+0xf7a/0x1340 kernel/rcu/tree_stall.h:681
check_cpu_stall kernel/rcu/tree_stall.h:857 [inline]
rcu_pending kernel/rcu/tree.c:3671 [inline]
rcu_sched_clock_irq+0xa47/0x11b0 kernel/rcu/tree.c:2706
update_process_times+0x23c/0x2f0 kernel/time/timer.c:2473
tick_sched_handle kernel/time/tick-sched.c:276 [inline]
tick_nohz_handler+0x39a/0x520 kernel/time/tick-sched.c:297
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x4dd/0xc60 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
__sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1058
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:arch_stack_walk+0x123/0x150 arch/x86/kernel/stacktrace.c:24
Code: 5a 09 00 48 85 c0 74 24 48 89 df 48 89 c6 4d 89 f3 2e e8 50 75 96 1e 84 c0 74 11 4c 89 ff e8 14 5c 09 00 83 bd 78 ff ff ff 00 <75> cf 65 48 8b 05 a3 4f 27 11 48 3b 45 d8 75 12 48 83 c4 68 5b 41
RSP: 0018:ffffc90000006cc8 EFLAGS: 00000202
RAX: 00000000903b1401 RBX: ffffc90000006d80 RCX: 70ecd254e2432500
RDX: 0000000000000006 RSI: ffffffff8d9d1700 RDI: ffff88802ba9bc80
RBP: ffffc90000006d50 R08: ffffc90002ef7ea0 R09: 0000000000000000
R10: ffffc90000006d18 R11: fffff52000000da5 R12: ffff88802ba9bc80
R13: 00000000000002c0 R14: ffffffff81abbce0 R15: ffffc90000006cc8
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
unpoison_slab_object mm/kasan/common.c:342 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4947 [inline]
slab_alloc_node mm/slub.c:5246 [inline]
kmem_cache_alloc_node_noprof+0x433/0x710 mm/slub.c:5298
kmalloc_reserve+0xbd/0x290 net/core/skbuff.c:579
__alloc_skb+0x142/0x2d0 net/core/skbuff.c:670
alloc_skb include/linux/skbuff.h:1383 [inline]
synproxy_send_client_synack_ipv6+0x169/0xca0 net/netfilter/nf_synproxy_core.c:873
nft_synproxy_eval_v6+0x36e/0x560 net/netfilter/nft_synproxy.c:90
nft_synproxy_do_eval+0x3d7/0x570 net/netfilter/nft_synproxy.c:145
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x409/0x1920 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:158 [inline]
nf_hook_slow+0xc2/0x220 net/netfilter/core.c:623
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:316
ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:500
NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6079 [inline]
__netif_receive_skb+0xd3/0x380 net/core/dev.c:6192
process_backlog+0x60e/0x14f0 net/core/dev.c:6544
__napi_poll+0xc7/0x360 net/core/dev.c:7594
napi_poll net/core/dev.c:7657 [inline]
net_rx_action+0x5f7/0xdf0 net/core/dev.c:7784
handle_softirqs+0x283/0x870 kernel/softirq.c:622
do_softirq+0xec/0x180 kernel/softirq.c:523
__local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:450
spin_unlock_bh include/linux/spinlock.h:396 [inline]
nl80211_netlink_notify+0x6f4/0x840 net/wireless/nl80211.c:21521
notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380
netlink_release+0x1280/0x1b40 net/netlink/af_netlink.c:763
__sock_release net/socket.c:662 [inline]
sock_close+0xc0/0x240 net/socket.c:1455
__fput+0x44c/0xa70 fs/file_table.c:468
fput_close_sync+0x119/0x200 fs/file_table.c:573
__do_sys_close fs/open.c:1589 [inline]
__se_sys_close fs/open.c:1574 [inline]
__ia32_sys_close+0x7f/0x110 fs/open.c:1574
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0xb6/0x2b0 arch/x86/entry/syscall_32.c:306
do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf706d539
Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f4bd44f0 EFLAGS: 00000206 ORIG_RAX: 0000000000000006
RAX: ffffffffffffffda RBX: 000000000000000b RCX: 00000000f4bd5b40
RDX: 0000000000000000 RSI: 00000000f7405ff4 RDI: 00000000f7405ff4
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 473 jiffies! g17833 f0x0 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:27320 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 0 UID: 0 PID: 6791 Comm: syz.2.239 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:arch_stack_walk+0x123/0x150 arch/x86/kernel/stacktrace.c:24
Code: 5a 09 00 48 85 c0 74 24 48 89 df 48 89 c6 4d 89 f3 2e e8 50 75 96 1e 84 c0 74 11 4c 89 ff e8 14 5c 09 00 83 bd 78 ff ff ff 00 <75> cf 65 48 8b 05 a3 4f 27 11 48 3b 45 d8 75 12 48 83 c4 68 5b 41
RSP: 0018:ffffc90000006cc8 EFLAGS: 00000202
RAX: 00000000903b1401 RBX: ffffc90000006d80 RCX: 70ecd254e2432500
RDX: 0000000000000006 RSI: ffffffff8d9d1700 RDI: ffff88802ba9bc80
RBP: ffffc90000006d50 R08: ffffc90002ef7ea0 R09: 0000000000000000
R10: ffffc90000006d18 R11: fffff52000000da5 R12: ffff88802ba9bc80
R13: 00000000000002c0 R14: ffffffff81abbce0 R15: ffffc90000006cc8
FS: 0000000000000000(0000) GS:ffff888125d0f000(0063) knlGS:00000000f4bd5b40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f73c9dec CR3: 000000002d7dc000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
unpoison_slab_object mm/kasan/common.c:342 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4947 [inline]
slab_alloc_node mm/slub.c:5246 [inline]
kmem_cache_alloc_node_noprof+0x433/0x710 mm/slub.c:5298
kmalloc_reserve+0xbd/0x290 net/core/skbuff.c:579
__alloc_skb+0x142/0x2d0 net/core/skbuff.c:670
alloc_skb include/linux/skbuff.h:1383 [inline]
synproxy_send_client_synack_ipv6+0x169/0xca0 net/netfilter/nf_synproxy_core.c:873
nft_synproxy_eval_v6+0x36e/0x560 net/netfilter/nft_synproxy.c:90
nft_synproxy_do_eval+0x3d7/0x570 net/netfilter/nft_synproxy.c:145
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x409/0x1920 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:158 [inline]
nf_hook_slow+0xc2/0x220 net/netfilter/core.c:623
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:316
ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:500
NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6079 [inline]
__netif_receive_skb+0xd3/0x380 net/core/dev.c:6192
process_backlog+0x60e/0x14f0 net/core/dev.c:6544
__napi_poll+0xc7/0x360 net/core/dev.c:7594
napi_poll net/core/dev.c:7657 [inline]
net_rx_action+0x5f7/0xdf0 net/core/dev.c:7784
handle_softirqs+0x283/0x870 kernel/softirq.c:622
do_softirq+0xec/0x180 kernel/softirq.c:523
__local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:450
spin_unlock_bh include/linux/spinlock.h:396 [inline]
nl80211_netlink_notify+0x6f4/0x840 net/wireless/nl80211.c:21521
notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380
netlink_release+0x1280/0x1b40 net/netlink/af_netlink.c:763
__sock_release net/socket.c:662 [inline]
sock_close+0xc0/0x240 net/socket.c:1455
__fput+0x44c/0xa70 fs/file_table.c:468
fput_close_sync+0x119/0x200 fs/file_table.c:573
__do_sys_close fs/open.c:1589 [inline]
__se_sys_close fs/open.c:1574 [inline]
__ia32_sys_close+0x7f/0x110 fs/open.c:1574
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0xb6/0x2b0 arch/x86/entry/syscall_32.c:306
do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf706d539
Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f4bd44f0 EFLAGS: 00000206 ORIG_RAX: 0000000000000006
RAX: ffffffffffffffda RBX: 000000000000000b RCX: 00000000f4bd5b40
RDX: 0000000000000000 RSI: 00000000f7405ff4 RDI: 00000000f7405ff4
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000