rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=a1dc/1/0x4000000000000000 softirq=22006/22007 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5983/1:b..l P49 rcu: (detected by 0, t=10502 jiffies, g=14525, q=270 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 49 Comm: kworker/u8:3 Not tainted 6.15.0-syzkaller-12426-ge271ed52b344 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:_raw_spin_lock_irqsave+0x42/0x60 kernel/locking/spinlock.c:162 Code: 00 e8 d2 b0 07 f6 ff 74 24 10 48 8d 7b 18 45 31 c9 31 c9 41 b8 01 00 00 00 31 d2 31 f6 e8 96 ca 16 f6 48 89 df e8 7e 13 17 f6 <58> 48 89 e8 5b 5d c3 cc cc cc cc e8 6e 35 42 f6 eb c0 66 66 2e 0f RSP: 0018:ffffc90000a08d00 EFLAGS: 00000092 RAX: 0000000000000000 RBX: ffffffff9af80920 RCX: ffffffff8198c7dc RDX: 1ffffffff35f0126 RSI: 0000000000000004 RDI: ffffc90000a08c90 RBP: 0000000000000002 R08: 0000000000000001 R09: fffff52000141192 R10: 0000000000000003 R11: 0000000000000001 R12: dffffc0000000000 R13: ffff88802541c340 R14: ffffffff9af80918 R15: 1ffff920001411a8 FS: 0000000000000000(0000) GS:ffff88812485a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055555cabe808 CR3: 000000006092b000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_object_activate+0x14c/0x4c0 lib/debugobjects.c:818 debug_hrtimer_activate kernel/time/hrtimer.c:445 [inline] debug_activate kernel/time/hrtimer.c:484 [inline] enqueue_hrtimer+0x23/0x3b0 kernel/time/hrtimer.c:1088 __run_hrtimer kernel/time/hrtimer.c:1778 [inline] __hrtimer_run_queues+0x8ff/0xad0 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x3f0 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:finish_task_switch.isra.0+0x22a/0xc10 kernel/sched/core.c:5264 Code: fb 09 00 00 44 8b 05 89 53 1e 0f 45 85 c0 0f 85 be 01 00 00 4c 89 e7 e8 a4 f6 ff ff e8 1f 08 3a 00 fb 65 48 8b 1d 3e 81 42 12 <48> 8d bb 18 16 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 RSP: 0018:ffffc90000ba7760 EFLAGS: 00000202 RAX: 000000000006c3d9 RBX: ffff888021ecc880 RCX: 0000000000000006 RDX: 0000000000000000 RSI: ffffffff8de14dcb RDI: ffffffff8c157060 RBP: ffffc90000ba77a8 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90a80057 R11: 0000000000000001 R12: ffff8880b853bc80 R13: ffff8880352a4880 R14: ffff88807bd55600 R15: ffff8880b853caf0 context_switch kernel/sched/core.c:5399 [inline] __schedule+0x1172/0x5de0 kernel/sched/core.c:6785 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7108 irqentry_exit+0x36/0x90 kernel/entry/common.c:307 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5875 Code: e2 33 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 42 82 0f 0f 0f 82 74 02 00 00 8b 35 2a b4 0f 0f 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 d9 e1 33 12 0f 85 c7 02 00 00 48 83 c4 RSP: 0018:ffffc90000ba7a40 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e5c4cc0 RCX: 0000000095aa05c5 RDX: 0000000000000000 RSI: ffffffff8ddef823 RDI: ffffffff8c157060 RBP: 0000000000000002 R08: 9500627d63e3edae R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] batadv_nc_process_nc_paths.part.0+0xe4/0x3e0 net/batman-adv/network-coding.c:687 batadv_nc_process_nc_paths net/batman-adv/network-coding.c:679 [inline] batadv_nc_worker+0xcd3/0x1030 net/batman-adv/network-coding.c:728 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:kworker/u8:3 state:R running task stack:25656 pid:49 tgid:49 ppid:2 task_flags:0x4208060 flags:0x00004008 Workqueue: bat_events batadv_nc_worker Call Trace: task:kworker/u8:9 state:R running task stack:24472 pid:5983 tgid:5983 ppid:2 task_flags:0x4208160 flags:0x00004000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7108 irqentry_exit+0x36/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_release+0x183/0x2f0 kernel/locking/lockdep.c:5896 Code: 0f c1 05 58 29 34 12 83 f8 01 0f 85 1d 01 00 00 9c 58 f6 c4 02 0f 85 08 01 00 00 41 f7 c5 00 02 00 00 74 01 fb 48 8b 44 24 10 <65> 48 2b 05 6d e7 33 12 0f 85 58 01 00 00 48 83 c4 18 5b 41 5c 41 RSP: 0018:ffffc900058b76b0 EFLAGS: 00000206 RAX: 3ccf6fb992d0c200 RBX: ffffffff8e5c4cc0 RCX: ffffc900058b76bc RDX: 0000000000000003 RSI: ffffffff8ddef823 RDI: ffffffff8c157060 RBP: 0000000000000001 R08: ffffffff9141be04 R09: 0000000000000000 R10: 0000000000000000 R11: 000000000000a77e R12: ffffffff816acbe4 R13: 0000000000000206 R14: ffff88807f5f4880 R15: 0000000000000004 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x3f9/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kmem_cache_free+0x2d1/0x4d0 mm/slub.c:4745 kfree_skbmem+0x1a4/0x1f0 net/core/skbuff.c:1110 __kfree_skb net/core/skbuff.c:1167 [inline] sk_skb_reason_drop+0x136/0x1a0 net/core/skbuff.c:1204 kfree_skb_reason include/linux/skbuff.h:1275 [inline] kfree_skb include/linux/skbuff.h:1284 [inline] ieee80211_iface_work+0x434/0x1020 net/mac80211/iface.c:1724 cfg80211_wiphy_work+0x3dc/0x550 net/wireless/core.c:435 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 10502 jiffies! g14525 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:28744 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6878 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2256 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 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: 0 UID: 0 PID: 36 Comm: kworker/u8:2 Not tainted 6.15.0-syzkaller-12426-ge271ed52b344 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0xd7b/0x1510 kernel/smp.c:885 Code: e8 1a 17 0c 00 45 85 ed 74 46 48 8b 14 24 49 89 d6 49 89 d5 49 c1 ee 03 41 83 e5 07 4d 01 e6 41 83 c5 03 e8 b7 1b 0c 00 f3 90 <41> 0f b6 06 41 38 c5 7c 08 84 c0 0f 85 6f 05 00 00 8b 43 08 31 ff RSP: 0018:ffffc90000ac78a0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b85417e0 RCX: ffffffff81affabd RDX: ffff888021afc880 RSI: ffffffff81affa99 RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000 R13: 0000000000000003 R14: ffffed10170a82fd R15: ffff8880b843cf40 FS: 0000000000000000(0000) GS:ffff88812475a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f30bff8 CR3: 000000000e382000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2660 [inline] smp_text_poke_batch_finish+0x27b/0xdb0 arch/x86/kernel/alternative.c:2870 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x376/0x550 kernel/jump_label.c:919 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate mm/kfence/core.c:850 [inline] toggle_allocation_gate+0xfa/0x280 mm/kfence/core.c:842 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245