rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P56/1:b..l rcu: (detected by 0, t=10539 jiffies, g=15353, q=3288 ncpus=2) task:kworker/1:1 state:R running task stack:25752 pid:56 tgid:56 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0xfe4/0x5e10 kernel/sched/core.c:6867 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7194 irqentry_exit+0x17b/0x670 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__seqprop_spinlock_sequence include/linux/seqlock.h:227 [inline] RIP: 0010:nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:342 [inline] RIP: 0010:gc_worker+0x2bb/0x1630 net/netfilter/nf_conntrack_core.c:1548 Code: 00 00 48 c7 c7 28 fe b7 90 e8 61 e7 4a f8 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 ff be 6e f8 58 48 85 db 0f 85 97 0f 00 00 10 c4 6e f8 8b 1d aa c2 1f 07 89 dd 31 ff 83 e5 01 89 ee e8 ac RSP: 0018:ffffc9000121fae0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff89984606 RDX: ffff888022eac980 RSI: ffffffff89984615 RDI: ffff888022eac980 RBP: 000000000005fe01 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: 0000000000040000 R14: 000000000002ff01 R15: 0000000000001770 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3421 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: rcu_preempt kthread timer wakeup didn't happen for 4064 jiffies! g15353 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=7154 rcu: rcu_preempt kthread starved for 4065 jiffies! g15353 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28408 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0xfe4/0x5e10 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0xdd/0x390 kernel/sched/core.c:6964 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0xb00 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x21e/0x320 kernel/rcu/tree.c:2285 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 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: 80 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:trace_hrtimer_cancel+0x11/0x1d0 include/trace/events/timer.h:317 Code: 5b e9 13 dc fc 02 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 48 89 fd 53 e8 c6 0a 14 00 66 90 e8 bf 0a 14 00 <65> 8b 1d 6c 7b f1 11 bf 07 00 00 00 89 de e8 5c 05 14 00 83 fb 07 RSP: 0000:ffffc90000a08e38 EFLAGS: 00000046 RAX: 0000000000010001 RBX: 0000000000000001 RCX: 0000000000000000 RDX: ffff88801cbaa4c0 RSI: ffffffff81f2f4c1 RDI: ffff888076db2300 RBP: ffff888076db2300 R08: 0000000000000000 R09: fffffbfff3634d4f R10: ffffffff9b1a6a7b R11: 0000000000000001 R12: ffff8880b8528440 R13: ffff888076db2300 R14: ffff8880b8528540 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881246d9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb02659a5d8 CR3: 000000006e95c000 CR4: 00000000003526f0 Call Trace: debug_deactivate kernel/time/hrtimer.c:484 [inline] __run_hrtimer kernel/time/hrtimer.c:1745 [inline] __hrtimer_run_queues+0x39d/0x990 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x397/0x8c0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x109/0x3c0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:unwind_next_frame+0xbe1/0x1ea0 arch/x86/kernel/unwind_orc.c:656 Code: 00 00 00 fc ff df 48 c1 e8 03 0f b6 34 10 49 8d 40 01 48 89 c7 48 c1 ef 03 0f b6 14 17 4c 89 c7 83 e7 07 40 38 fe 40 0f 9e c7 <40> 84 f6 40 0f 95 c6 40 84 f7 0f 85 0a 0d 00 00 83 e0 07 38 c2 40 RSP: 0000:ffffc9000218f5f0 EFLAGS: 00000297 RAX: ffffffff91fe8a3f RBX: 0000000000000001 RCX: ffffffff91fe8a3a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffffc9000218f6a8 R08: ffffffff91fe8a3e R09: 0000000000000007 R10: 0000000000000200 R11: 000000000009ecff R12: ffffc9000218f6b0 R13: ffffc9000218f660 R14: ffffc9000218fb90 R15: ffffc9000218f694 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6674 [inline] kmem_cache_free+0x143/0x720 mm/slub.c:6789 skb_kfree_head net/core/skbuff.c:1066 [inline] skb_kfree_head net/core/skbuff.c:1063 [inline] skb_free_head+0x1c6/0x220 net/core/skbuff.c:1080 skb_release_data+0x540/0x700 net/core/skbuff.c:1107 skb_release_all net/core/skbuff.c:1182 [inline] __kfree_skb net/core/skbuff.c:1196 [inline] sk_skb_reason_drop+0x102/0x1b0 net/core/skbuff.c:1234 kfree_skb_reason include/linux/skbuff.h:1322 [inline] kfree_skb include/linux/skbuff.h:1331 [inline] ieee80211_iface_work+0x46f/0x1350 net/mac80211/iface.c:1796 cfg80211_wiphy_work+0x3f7/0x560 net/wireless/core.c:438 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3421 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 sched: DL replenish lagged too much