------------[ cut here ]------------
WARNING: kernel/rcu/tree_stall.h:1049 at rcu_check_gp_start_stall+0x2e4/0x470 kernel/rcu/tree_stall.h:1049, CPU#0: syz.3.33/6136
Modules linked in:
CPU: 0 UID: 0 PID: 6136 Comm: syz.3.33 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:rcu_check_gp_start_stall+0x2e4/0x470 kernel/rcu/tree_stall.h:1049
Code: ff ff 48 c7 c7 a0 c5 d3 99 be 04 00 00 00 e8 83 35 80 00 4c 89 f7 b8 01 00 00 00 87 05 95 57 2b 18 85 c0 0f 85 17 ff ff ff 90 <0f> 0b 90 48 81 ff c0 46 34 8e 74 47 48 c7 c0 a0 00 c4 8f 48 c1 e8
RSP: 0018:ffffc90000007b78 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000a06 RCX: ffffffff81a86dfd
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8e3446c0
RBP: ffffc90000007e30 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff33a78b4 R12: 0000000000002904
R13: 1ffff110170c7762 R14: ffffffff8e3446c0 R15: dffffc0000000000
FS:  00007fda684b46c0(0000) GS:ffff8881259dc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f72fb7156c0 CR3: 000000002ebfc000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 rcu_core+0x6a9/0x1870 kernel/rcu/tree.c:2852
 handle_softirqs+0x27d/0x850 kernel/softirq.c:626
 __do_softirq kernel/softirq.c:660 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:727
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:743
 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 0b f4 5f f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 23 6b 27 f6 65 8b 05 7c 60 5a 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc900030c7320 EFLAGS: 00000206
RAX: c3c777889b59ab00 RBX: 0000000000000a06 RCX: c3c777889b59ab00
RDX: 0000000000000007 RSI: ffffffff8daa9dc3 RDI: 0000000000000001
RBP: ffffc900030c73b0 R08: ffffffff8fc3d077 R09: 1ffffffff1f87a0e
R10: dffffc0000000000 R11: fffffbfff1f87a0f R12: dffffc0000000000
R13: 0000000000000000 R14: ffff8880b8628240 R15: 1ffff92000618e64
 hrtimer_start include/linux/hrtimer.h:259 [inline]
 stimer_start arch/x86/kvm/hyperv.c:682 [inline]
 kvm_hv_process_stimers+0xd0a/0x16a0 arch/x86/kvm/hyperv.c:893
 vcpu_enter_guest arch/x86/kvm/x86.c:11193 [inline]
 vcpu_run+0x2240/0x76b0 arch/x86/kvm/x86.c:11639
 kvm_arch_vcpu_ioctl_run+0x1148/0x1c90 arch/x86/kvm/x86.c:11984
 kvm_vcpu_ioctl+0x99a/0xed0 virt/kvm/kvm_main.c:4492
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fda6758f749
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:00007fda684b4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fda677e5fa0 RCX: 00007fda6758f749
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 00007fda67613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fda677e6038 R14: 00007fda677e5fa0 R15: 00007ffec07adae8
 </TASK>
----------------
Code disassembly (best guess):
   0:	74 05                	je     0x7
   2:	e8 0b f4 5f f6       	call   0xf65ff412
   7:	48 c7 44 24 20 00 00 	movq   $0x0,0x20(%rsp)
   e:	00 00
  10:	9c                   	pushf
  11:	8f 44 24 20          	pop    0x20(%rsp)
  15:	f6 44 24 21 02       	testb  $0x2,0x21(%rsp)
  1a:	75 4f                	jne    0x6b
  1c:	f7 c3 00 02 00 00    	test   $0x200,%ebx
  22:	74 01                	je     0x25
  24:	fb                   	sti
  25:	bf 01 00 00 00       	mov    $0x1,%edi
* 2a:	e8 23 6b 27 f6       	call   0xf6276b52 <-- trapping instruction
  2f:	65 8b 05 7c 60 5a 07 	mov    %gs:0x75a607c(%rip),%eax        # 0x75a60b2
  36:	85 c0                	test   %eax,%eax
  38:	74 40                	je     0x7a
  3a:	48                   	rex.W
  3b:	c7                   	.byte 0xc7
  3c:	04 24                	add    $0x24,%al
  3e:	0e                   	(bad)
  3f:	36                   	ss