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WARNING: kernel/rcu/tree_stall.h:1049 at rcu_check_gp_start_stall+0x2e4/0x470 kernel/rcu/tree_stall.h:1049, CPU#0: kworker/u8:0/12
Modules linked in:
CPU: 0 UID: 0 PID: 12 Comm: kworker/u8:0 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:rcu_check_gp_start_stall+0x2e4/0x470 kernel/rcu/tree_stall.h:1049
Code: ff ff 48 c7 c7 c0 95 27 9a be 04 00 00 00 e8 73 9f 83 00 4c 89 f7 b8 01 00 00 00 87 05 65 7f 7d 18 85 c0 0f 85 17 ff ff ff 90 <0f> 0b 90 48 81 ff 00 3f 76 8e 74 47 48 c7 c0 d0 2d 11 90 48 c1 e8
RSP: 0000:ffffc90000007db8 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000246 RCX: ffffffff81aa164d
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8e763f00
RBP: ffffc90000007f30 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff344f2b8 R12: 0000000000002904
R13: dffffc0000000000 R14: ffffffff8e763f00 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881254a0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000f73c39b4 CR3: 000000000e54a000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0400000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_core+0x3fe/0x1070 kernel/rcu/tree.c:2864
 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:check_kcov_mode kernel/kcov.c:194 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x36/0x70 kernel/kcov.c:217
Code: d8 bc 53 11 65 8b 15 f9 bc 53 11 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 54 16 00 00 00 74 2c 8b 91 30 16 00 00 <83> fa 02 75 21 48 8b 91 38 16 00 00 48 8b 32 48 8d 7e 01 8b 89 34
RSP: 0000:ffffc90000117718 EFLAGS: 00000246
RAX: ffffffff81b86d6d RBX: 1ffff110170e80ed RCX: ffff88801d6f8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000117860 R08: ffffffff9010fb77 R09: 1ffffffff2021f6e
R10: dffffc0000000000 R11: fffffbfff2021f6f R12: ffff8880b8740768
R13: dffffc0000000000 R14: ffff8880b863bd80 R15: 0000000000000001
 csd_lock_wait kernel/smp.c:342 [inline]
 smp_call_function_many_cond+0xcfd/0x1270 kernel/smp.c:877
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
 on_each_cpu include/linux/smp.h:72 [inline]
 smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2746 [inline]
 smp_text_poke_batch_finish+0x5f5/0x1160 arch/x86/kernel/alternative.c:2956
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:899
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3358
 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
 kthread+0x388/0x470 kernel/kthread.c:467
 ret_from_fork+0x51e/0xb90 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:	d8 bc 53 11 65 8b 15 	fdivrs 0x158b6511(%rbx,%rdx,2)
   7:	f9                   	stc
   8:	bc 53 11 81 e2       	mov    $0xe2811153,%esp
   d:	00 01                	add    %al,(%rcx)
   f:	ff 00                	incl   (%rax)
  11:	74 11                	je     0x24
  13:	81 fa 00 01 00 00    	cmp    $0x100,%edx
  19:	75 35                	jne    0x50
  1b:	83 b9 54 16 00 00 00 	cmpl   $0x0,0x1654(%rcx)
  22:	74 2c                	je     0x50
  24:	8b 91 30 16 00 00    	mov    0x1630(%rcx),%edx
* 2a:	83 fa 02             	cmp    $0x2,%edx <-- trapping instruction
  2d:	75 21                	jne    0x50
  2f:	48 8b 91 38 16 00 00 	mov    0x1638(%rcx),%rdx
  36:	48 8b 32             	mov    (%rdx),%rsi
  39:	48 8d 7e 01          	lea    0x1(%rsi),%rdi
  3d:	8b                   	.byte 0x8b
  3e:	89                   	.byte 0x89
  3f:	34                   	.byte 0x34