rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P19047/1:b..l rcu: (detected by 0, t=10503 jiffies, g=99497, q=740585 ncpus=2) task:syz.2.3120 state:R running task stack:24128 pid:19047 tgid:19046 ppid:18502 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:sctp_v6_cmp_addr+0x15/0xd0 net/sctp/ipv6.c:668 Code: 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 53 48 89 f3 49 89 fe e8 ab b2 b7 f6 <4c> 89 f7 48 89 de e8 c0 c2 ff ff 41 89 c7 31 ed 31 ff 89 c6 e8 d2 RSP: 0018:ffffc90006c47a30 EFLAGS: 00000283 RAX: ffffffff8b0ebf15 RBX: ffffc90006c47b00 RCX: 0000000000080000 RDX: ffffc9000da22000 RSI: 00000000000153e4 RDI: 00000000000153e5 RBP: 0000000000000001 R08: ffff888086ea9f00 R09: 0000000000000002 R10: 000000000000000a R11: ffffffff8b0ebf00 R12: ffffffff90272050 R13: ffff8880749ee03d R14: ffff8880749ee020 R15: ffff8880749ee000 sctp_bind_addr_state+0xd2/0x1b0 net/sctp/bind_addr.c:422 sctp_copy_local_addr_list+0x2e2/0x4e0 net/sctp/protocol.c:165 sctp_bind_addr_copy+0xb3/0x3c0 net/sctp/bind_addr.c:56 sctp_connect_new_asoc+0x2ff/0x6b0 net/sctp/socket.c:1096 __sctp_connect+0x5cb/0xdc0 net/sctp/socket.c:1198 sctp_setsockopt_connectx_old net/sctp/socket.c:1348 [inline] sctp_setsockopt+0x480/0x12c0 net/sctp/socket.c:4626 do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2368 __sys_setsockopt net/socket.c:2393 [inline] __do_sys_setsockopt net/socket.c:2399 [inline] __se_sys_setsockopt net/socket.c:2396 [inline] __x64_sys_setsockopt+0x13d/0x1b0 net/socket.c:2396 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f495b99de59 RSP: 002b:00007f495c918028 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f495bc25fa0 RCX: 00007f495b99de59 RDX: 000000000000006b RSI: 0000000000000084 RDI: 0000000000000009 RBP: 00007f495ba33e6f R08: 000000000000001c R09: 0000000000000000 R10: 0000200000000380 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f495bc26038 R14: 00007f495bc25fa0 R15: 00007ffd8ba45418 rcu: rcu_preempt kthread starved for 602 jiffies! g99497 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325 kthread+0x388/0x470 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: 1175 Comm: kworker/u8:9 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:__preempt_count_add arch/x86/include/asm/preempt.h:80 [inline] RIP: 0010:rcu_is_watching+0x9/0xb0 kernel/rcu/tree.c:751 Code: 64 03 eb cc 66 66 66 66 2e 0f 1f 84 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 f0 b2 c0 11 e8 bb 14 23 0a 89 c3 83 f8 08 73 65 49 bf 00 RSP: 0018:ffffc90000a07f00 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffffff8998da54 RCX: ffff88802912dd00 RDX: 00000000a42637f2 RSI: ffffffff8e4afaa3 RDI: ffffffff8c4bd280 RBP: 1ffff92000141000 R08: ffffffff8176f21f R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb59c20 R12: dffffc0000000000 R13: ffffffff8176f21f R14: ffffc90000a07fc8 R15: 1ffff92000140ff9 FS: 0000000000000000(0000) GS:ffff888125060000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f526923b22f CR3: 00000000362d0000 CR4: 00000000003526f0 Call Trace: rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1183 [inline] unwind_next_frame+0xbe/0x2550 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 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3159 [inline] call_rcu+0xee/0x8b0 kernel/rcu/tree.c:3279 refdst_drop include/net/dst.h:272 [inline] skb_dst_drop include/net/dst.h:284 [inline] skb_release_head_state+0x71/0x360 net/core/skbuff.c:1165 skb_release_all net/core/skbuff.c:1189 [inline] __kfree_skb+0x24/0x210 net/core/skbuff.c:1205 nft_synproxy_eval_v4+0x36a/0x4e0 net/netfilter/nft_synproxy.c:-1 nft_synproxy_do_eval+0x335/0x550 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x48d/0x1b10 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:165 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:280 [inline] NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:323 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:325 __netif_receive_skb_one_core net/core/dev.c:6209 [inline] __netif_receive_skb net/core/dev.c:6322 [inline] process_backlog+0xa34/0x1860 net/core/dev.c:6673 __napi_poll+0xaa/0x330 net/core/dev.c:7732 napi_poll net/core/dev.c:7795 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:7952 handle_softirqs+0x225/0x840 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 ieee80211_rx_bss_info net/mac80211/ibss.c:1136 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1545 [inline] ieee80211_ibss_rx_queued_mgmt+0x1e3f/0x2be0 net/mac80211/ibss.c:1572 ieee80211_iface_process_skb net/mac80211/iface.c:1763 [inline] ieee80211_iface_work+0x78a/0x1010 net/mac80211/iface.c:1817 cfg80211_wiphy_work+0x29e/0x420 net/wireless/core.c:538 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 kthread+0x388/0x470 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