syzbot

 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
watchdog: BUG: soft lockup - CPU#0 stuck for 226s! [kworker/u8:28:29187]
Modules linked in:
irq event stamp: 4377077
hardirqs last  enabled at (4377076): [<ffffffff8b61aac2>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
hardirqs last  enabled at (4377076): [<ffffffff8b61aac2>] _raw_spin_unlock_irqrestore+0x52/0x80 kernel/locking/spinlock.c:194
hardirqs last disabled at (4377077): [<ffffffff8b5ee7ce>] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1052
softirqs last  enabled at (4377040): [<ffffffff817d237e>] softirq_handle_end kernel/softirq.c:468 [inline]
softirqs last  enabled at (4377040): [<ffffffff817d237e>] handle_softirqs+0x5be/0x8e0 kernel/softirq.c:650
softirqs last disabled at (4377049): [<ffffffff817d2839>] __do_softirq kernel/softirq.c:656 [inline]
softirqs last disabled at (4377049): [<ffffffff817d2839>] invoke_softirq kernel/softirq.c:496 [inline]
softirqs last disabled at (4377049): [<ffffffff817d2839>] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723
CPU: 0 UID: 0 PID: 29187 Comm: kworker/u8:28 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:debug_lockdep_rcu_enabled+0x0/0x40 kernel/rcu/update.c:319
Code: 00 00 00 eb b6 e8 30 fa ff ff eb b6 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 8b 05 76 58 23 05 85 c0 74 20 8b 05 e0 87 23 05 85 c0
RSP: 0018:ffffc900000075b0 EFLAGS: 00000283
RAX: ffffc9000b448001 RBX: ffffc9000b447c50 RCX: ffffc9000b448001
RDX: ffffc9000b447c58 RSI: ffffc9000b447c40 RDI: ffffc90000007638
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 00000000000124bf R12: ffffc90000007678
R13: ffffc90000007628 R14: ffffc9000b447c50 R15: ffffc9000000765c
FS:  0000000000000000(0000) GS:ffff888124a06000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5133bb7f18 CR3: 000000000e182000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 rcu_read_unlock include/linux/rcupdate.h:895 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0x3de/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:56
 kasan_save_track+0x14/0x30 mm/kasan/common.c:77
 unpoison_slab_object mm/kasan/common.c:342 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:368
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4978 [inline]
 slab_alloc_node mm/slub.c:5288 [inline]
 kmem_cache_alloc_node_noprof+0x28a/0x770 mm/slub.c:5340
 kmalloc_reserve+0x18b/0x2c0 net/core/skbuff.c:579
 __alloc_skb+0x166/0x380 net/core/skbuff.c:670
 __netdev_alloc_skb+0x213/0x920 net/core/skbuff.c:734
 netdev_alloc_skb include/linux/skbuff.h:3484 [inline]
 dev_alloc_skb include/linux/skbuff.h:3497 [inline]
 __ieee80211_beacon_get+0xab1/0x1e40 net/mac80211/tx.c:5652
 ieee80211_beacon_get_tim+0xa6/0x280 net/mac80211/tx.c:5774
 ieee80211_beacon_get include/net/mac80211.h:5667 [inline]
 mac80211_hwsim_beacon_tx+0x4dc/0xa40 drivers/net/wireless/virtual/mac80211_hwsim.c:2361
 __iterate_interfaces+0x2e5/0x650 net/mac80211/util.c:761
 ieee80211_iterate_active_interfaces_atomic+0x71/0x1b0 net/mac80211/util.c:797
 mac80211_hwsim_beacon+0x105/0x1b0 drivers/net/wireless/virtual/mac80211_hwsim.c:2395
 __run_hrtimer kernel/time/hrtimer.c:1777 [inline]
 __hrtimer_run_queues+0x202/0xad0 kernel/time/hrtimer.c:1841
 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1858
 handle_softirqs+0x219/0x8e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1052
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xdfd/0x1600 kernel/smp.c:877
Code: 57 48 8b 54 24 10 4c 89 74 24 10 49 89 d5 48 89 d5 48 89 54 24 18 49 c1 ed 03 83 e5 07 4d 01 e5 83 c5 03 e8 75 0d 0c 00 f3 90 <41> 0f b6 45 00 40 38 c5 7c 08 84 c0 0f 85 e0 05 00 00 8b 43 08 31
RSP: 0018:ffffc9000b447878 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b8540460 RCX: ffffffff81b0da31
RDX: ffff88808170dac0 RSI: ffffffff81b0da0b RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000
R13: ffffed10170a808d R14: 0000000000000001 R15: 0000000000000001
 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1043
 on_each_cpu include/linux/smp.h:71 [inline]
 smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2713 [inline]
 smp_text_poke_batch_finish+0x27b/0xdb0 arch/x86/kernel/alternative.c:2923
 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:852 [inline]
 toggle_allocation_gate+0xfa/0x280 mm/kfence/core.c:844
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
 process_scheduled_works kernel/workqueue.c:3346 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 3975 Comm: syz.6.10046 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:rcu_preempt_read_enter kernel/rcu/tree_plugin.h:391 [inline]
RIP: 0010:__rcu_read_lock+0x65/0xf0 kernel/rcu/tree_plugin.h:414
Code: a6 00 00 00 65 48 8b 2d 61 fb ff 11 48 8d bd 84 04 00 00 8b 9b 84 04 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <83> c3 01 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2
RSP: 0018:ffffc90000a08d78 EFLAGS: 00000017
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 1ffff1100f270be8 RSI: 0000000000000004 RDI: ffff888079385f44
RBP: ffff888079385ac0 R08: 0000000000000000 R09: ffffed1002456a5d
R10: ffff8880122b52eb R11: 0000000000000001 R12: 1889f544fc000000
R13: 1889f544fc000000 R14: 0000000000000000 R15: ffff888025006400
FS:  00007f7163d636c0(0000) GS:ffff888124b06000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33e1bff8 CR3: 000000005a6fa000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 rcu_read_lock include/linux/rcupdate.h:865 [inline]
 advance_sched+0x676/0xc80 net/sched/sch_taprio.c:990
 __run_hrtimer kernel/time/hrtimer.c:1777 [inline]
 __hrtimer_run_queues+0x202/0xad0 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x3f0 arch/x86/kernel/apic/apic.c:1058
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1052
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:finish_task_switch.isra.0+0x22a/0xc10 kernel/sched/core.c:5193
Code: fb 09 00 00 44 8b 05 29 69 f8 0e 45 85 c0 0f 85 be 01 00 00 4c 89 e7 e8 a4 f6 ff ff e8 2f d3 3a 00 fb 65 48 8b 1d ee 89 17 12 <48> 8d bb 58 16 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1
RSP: 0018:ffffc9000402f4a8 EFLAGS: 00000206
RAX: 0000000000006b6f RBX: ffff888079385ac0 RCX: ffffffff81c4e84f
RDX: 0000000000000000 RSI: ffffffff8da2ae3d RDI: ffffffff8bf079c0
RBP: ffffc9000402f4f0 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff90824ed7 R11: 0000000000000001 R12: ffff8880b853a4c0
R13: ffff888032d53c80 R14: 0000000000000000 R15: dffffc0000000000
 context_switch kernel/sched/core.c:5328 [inline]
 __schedule+0x1198/0x5de0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7026
 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
 unix_wait_for_peer+0x24e/0x280 net/unix/af_unix.c:1639
 unix_dgram_sendmsg+0x1419/0x17f0 net/unix/af_unix.c:2273
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0xa98/0xc70 net/socket.c:2630
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2684
 __sys_sendmmsg+0x200/0x420 net/socket.c:2773
 __do_sys_sendmmsg net/socket.c:2800 [inline]
 __se_sys_sendmmsg net/socket.c:2797 [inline]
 __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2797
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7162f8f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7163d63038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f71631e5fa0 RCX: 00007f7162f8f749
RDX: 0000000000000651 RSI: 0000200000000000 RDI: 0000000000000004
RBP: 00007f7163013f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f71631e6038 R14: 00007f71631e5fa0 R15: 00007fffebfcbb48
 </TASK>