rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5758/1:b..l.. rcu: (detected by 1, t=10503 jiffies, g=91213, q=911952 ncpus=2) task:kworker/0:4 state:R running task stack:23880 pid:5758 tgid:5758 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events rht_deferred_worker Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5830 kernel/sched/core.c:7382 preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7662 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:543 [inline] irqentry_exit+0x14f/0x9b0 kernel/entry/common.c:154 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_release+0x2e1/0x3c0 kernel/locking/lockdep.c:5968 Code: 08 1c 13 00 00 00 00 eb b5 e8 8b 66 5e 0a f7 c3 00 02 00 00 74 b9 65 48 8b 05 93 c0 1b 13 48 3b 44 24 28 75 48 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 88 61 fc RSP: 0018:ffffc9000484f368 EFLAGS: 00000282 RAX: d96a840cb0dd7d00 RBX: 0000000000000206 RCX: 0000000000000046 RDX: ffffc9000484f401 RSI: ffffffff8e92d57d RDI: ffffffff8c8e8c80 RBP: ffff88802a086a10 R08: ffffc9000484f9b8 R09: 0000000000000000 R10: ffffc9000484f498 R11: fffff52000909e95 R12: 0000000000000004 R13: 0000000000000004 R14: ffffffff8ff5a320 R15: ffff88802a085dc0 rcu_lock_release include/linux/rcupdate.h:319 [inline] rcu_read_unlock include/linux/rcupdate.h:880 [inline] class_rcu_destructor include/linux/rcupdate.h:1216 [inline] unwind_next_frame+0x1baa/0x2550 arch/x86/kernel/unwind_orc.c:709 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:183 __reset_page_owner+0x73/0x2a0 mm/page_owner.c:338 reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1403 [inline] __free_frozen_pages+0xc97/0xd90 mm/page_alloc.c:2954 __slab_free+0x269/0x2c0 mm/slub.c:5926 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_kmalloc+0x22/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5531 [inline] __kvmalloc_node_noprof+0x50a/0x820 mm/slub.c:7136 bucket_table_alloc+0x78/0x390 lib/rhashtable.c:196 rhashtable_rehash_alloc+0x8e/0x170 lib/rhashtable.c:379 rht_deferred_worker+0x473/0x2090 lib/rhashtable.c:-1 process_one_work kernel/workqueue.c:3495 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659 kthread+0x38b/0x480 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: rcu_preempt kthread starved for 998 jiffies! g91213 f0x2 RCU_GP_WAIT_FQS(5) ->state=R ->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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5830 kernel/sched/core.c:7382 __schedule_loop kernel/sched/core.c:7459 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7474 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x1230 kernel/rcu/tree.c:2122 rcu_gp_kthread+0x9c/0x340 kernel/rcu/tree.c:2330 kthread+0x38b/0x480 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 13048 Comm: kworker/u8:23 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:write_comp_data kernel/kcov.c:251 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x8/0xb0 kernel/kcov.c:328 Code: 01 10 4a 89 74 01 18 4a 89 44 01 20 e9 91 ae 3c 0a cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 15 18 f5 f6 12 65 48 8b 0d 18 f5 f6 12 f7 c1 00 01 00 ff RSP: 0000:ffffc90000006ba8 EFLAGS: 00000046 RAX: ffffffff8a06bfb8 RBX: ffffffff8a06bf88 RCX: ffff888066b08000 RDX: 00000000105209fd RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffffffff8a06bf88 R09: 0000000000000001 R10: dffffc0000000000 R11: ffffed10058c8a56 R12: ffff888026baa000 R13: ffff88802c645000 R14: dffffc0000000000 R15: ffff88802c645340 FS: 0000000000000000(0000) GS:ffff88812361f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fffca7af768 CR3: 000000000fd48000 CR4: 00000000003526f0 Call Trace: rcu_read_lock include/linux/rcupdate.h:850 [inline] advance_sched+0xa18/0xc80 net/sched/sch_taprio.c:1000 __run_hrtimer kernel/time/hrtimer.c:2075 [inline] __hrtimer_run_queues+0x3bc/0xa10 kernel/time/hrtimer.c:2132 hrtimer_interrupt+0x4cd/0xaa0 kernel/time/hrtimer.c:2251 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:check_kcov_mode kernel/kcov.c:179 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x18/0x80 kernel/kcov.c:223 Code: cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0d 28 fa f6 12 65 48 8b 15 28 fa f6 12 c2 00 01 00 ff 74 29 89 d6 81 e6 00 01 00 0f 81 fe 00 01 00 00 RSP: 0000:ffffc90000006f78 EFLAGS: 00000246 RAX: ffffffff89ccfaf1 RBX: 0000000000000001 RCX: ffff888066b08000 RDX: 8000000000000301 RSI: 0000000000000100 RDI: 0000000000000000 RBP: ffffc90000007230 R08: 0000000000000100 R09: 0000000000000000 R10: ffffc90000007130 R11: fffff52000000e34 R12: dffffc0000000000 R13: ffff88807b627800 R14: ffff88802c95d000 R15: ffff88814affe710 arch_static_branch arch/x86/include/asm/jump_label.h:37 [inline] trace_net_dev_queue include/trace/events/net.h:159 [inline] __dev_queue_xmit+0x631/0x3920 net/core/dev.c:5042 dev_queue_xmit include/linux/netdevice.h:3485 [inline] neigh_hh_output include/net/neighbour.h:538 [inline] neigh_output include/net/neighbour.h:552 [inline] ip_finish_output2+0xbda/0x10b0 net/ipv4/ip_output.c:236 NF_HOOK_COND include/linux/netfilter.h:314 [inline] ip_output+0x29f/0x450 net/ipv4/ip_output.c:437 synproxy_send_client_synack+0x89b/0xde0 net/netfilter/nf_synproxy_core.c:487 nft_synproxy_eval_v4+0x362/0x4e0 net/netfilter/nft_synproxy.c:59 nft_synproxy_do_eval+0x389/0x5d0 net/netfilter/nft_synproxy.c:142 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_ipv4+0x195/0x290 net/netfilter/nft_chain_filter.c:24 nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:633 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:6433 [inline] __netif_receive_skb net/core/dev.c:6546 [inline] process_backlog+0xa6b/0x18b0 net/core/dev.c:6897 __napi_poll+0xaa/0x330 net/core/dev.c:7977 napi_poll net/core/dev.c:8040 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:8197 handle_softirqs+0x265/0x8d0 kernel/softirq.c:669 do_softirq+0x77/0xd0 kernel/softirq.c:569 __local_bh_enable_ip+0x100/0x140 kernel/softirq.c:473 spin_unlock_bh include/linux/spinlock.h:407 [inline] cfg80211_inform_single_bss_data+0x1491/0x1be0 net/wireless/scan.c:2463 cfg80211_inform_bss_data+0x25b/0x3be0 net/wireless/scan.c:3303 cfg80211_inform_bss_frame_data+0x51a/0xae0 net/wireless/scan.c:3399 ieee80211_bss_info_update+0x772/0xa30 net/mac80211/scan.c:236 ieee80211_rx_bss_info net/mac80211/ibss.c:1065 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1546 [inline] ieee80211_ibss_rx_queued_mgmt+0x1ce1/0x2c40 net/mac80211/ibss.c:1573 ieee80211_iface_process_skb net/mac80211/iface.c:1805 [inline] ieee80211_iface_work+0x769/0xfa0 net/mac80211/iface.c:1859 cfg80211_wiphy_work+0x29e/0x420 net/wireless/core.c:610 process_one_work kernel/workqueue.c:3495 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659 kthread+0x38b/0x480 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