------------[ cut here ]------------
WARNING: CPU: 0 PID: 36 at kernel/rcu/tree_stall.h:1050 rcu_check_gp_start_stall+0x2e4/0x470 kernel/rcu/tree_stall.h:1050
Modules linked in:
CPU: 0 UID: 0 PID: 36 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:rcu_check_gp_start_stall+0x2e4/0x470 kernel/rcu/tree_stall.h:1050
Code: ff ff 48 c7 c7 80 c4 7d 99 be 04 00 00 00 e8 c3 23 7f 00 4c 89 f7 b8 01 00 00 00 87 05 25 da d6 17 85 c0 0f 85 17 ff ff ff 90 <0f> 0b 90 48 81 ff 40 29 f4 8d 74 47 48 c7 c0 90 10 7d 8f 48 c1 e8
RSP: 0018:ffffc90000007bb8 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000a02 RCX: ffffffff81a6ea4d
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8df42940
RBP: ffffc90000007e30 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff32fb890 R12: 0000000000002904
R13: 1ffff110171075f2 R14: ffffffff8df42940 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff88812613b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b34ffcff8 CR3: 000000000dd38000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 rcu_core+0x5fa/0x1770 kernel/rcu/tree.c:2856
 handle_softirqs+0x286/0x870 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x1f0 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+0xa6/0xc0 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:check_kcov_mode kernel/kcov.c:185 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x31/0x70 kernel/kcov.c:217
Code: 24 65 48 8b 0c 25 08 50 6e 92 65 8b 15 58 46 ae 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 7c 16 00 00 00 74 2c <8b> 91 58 16 00 00 83 fa 02 75 21 48 8b 91 60 16 00 00 48 8b 32 48
RSP: 0018:ffffc90000ac7638 EFLAGS: 00000246
RAX: ffffffff81b49a7b RBX: 1ffff11017127fed RCX: ffff888143681e40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000ac77c0 R08: ffffffff8f7ce077 R09: 1ffffffff1ef9c0e
R10: dffffc0000000000 R11: fffffbfff1ef9c0f R12: ffff8880b893ff68
R13: dffffc0000000000 R14: ffff8880b883b1c0 R15: 0000000000000001
 csd_lock_wait kernel/smp.c:342 [inline]
 smp_call_function_many_cond+0xd4b/0x12d0 kernel/smp.c:877
 on_each_cpu_cond_mask+0x3f/0x80 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+0x5f9/0x1130 arch/x86/kernel/alternative.c:2923
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x128/0x250 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:852
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
----------------
Code disassembly (best guess):
   0:	24 65                	and    $0x65,%al
   2:	48 8b 0c 25 08 50 6e 	mov    0xffffffff926e5008,%rcx
   9:	92
   a:	65 8b 15 58 46 ae 10 	mov    %gs:0x10ae4658(%rip),%edx        # 0x10ae4669
  11:	81 e2 00 01 ff 00    	and    $0xff0100,%edx
  17:	74 11                	je     0x2a
  19:	81 fa 00 01 00 00    	cmp    $0x100,%edx
  1f:	75 35                	jne    0x56
  21:	83 b9 7c 16 00 00 00 	cmpl   $0x0,0x167c(%rcx)
  28:	74 2c                	je     0x56
* 2a:	8b 91 58 16 00 00    	mov    0x1658(%rcx),%edx <-- trapping instruction
  30:	83 fa 02             	cmp    $0x2,%edx
  33:	75 21                	jne    0x56
  35:	48 8b 91 60 16 00 00 	mov    0x1660(%rcx),%rdx
  3c:	48 8b 32             	mov    (%rdx),%rsi
  3f:	48                   	rex.W