------------[ cut here ]------------
WARNING: kernel/rcu/tree_stall.h:1049 at rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1049, CPU#0: syz.5.1687/13637
Modules linked in:
CPU: 0 UID: 0 PID: 13637 Comm: syz.5.1687 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1049
Code: 88 61 01 00 00 be 04 00 00 00 48 c7 c7 c0 52 c2 9a e8 b0 3a 85 00 b8 01 00 00 00 87 05 25 c5 1e 19 85 c0 0f 85 3d 01 00 00 90 <0f> 0b 90 48 c7 c3 74 e5 88 90 48 81 fd 80 46 3d 8e 74 5a 48 b8 00
RSP: 0018:ffffc90000007df0 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000002904 RCX: ffffffff81a38d90
RDX: fffffbfff3584a58 RSI: 0000000000000004 RDI: ffffffff9ac252c0
RBP: ffffffff8e3d4680 R08: 0000000000000001 R09: fffffbfff3584a58
R10: 0000000000000003 R11: ffff888077882ff0 R12: 1ffffffff1c02250
R13: 0000000000000246 R14: ffffffff8e3d4680 R15: ffff8880b843bc52
FS:  000055555d917500(0000) GS:ffff8881248f5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055ae332842a0 CR3: 0000000055ee5000 CR4: 00000000003526f0
DR0: 0000000000000007 DR1: 00000000000001ff DR2: 0000000000000002
DR3: 000000000000006a DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_check_gp_start_stall kernel/rcu/tree_stall.h:1012 [inline]
 rcu_core+0x4cf/0x15f0 kernel/rcu/tree.c:2852
 handle_softirqs+0x219/0x950 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:1056 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 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_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202
Code: 90 f3 0f 1e fa 53 48 8b 74 24 08 48 89 fb 48 83 c7 18 e8 2a 0e 1f f6 48 89 df e8 e2 60 1f f6 e8 5d 22 4c f6 fb bf 01 00 00 00 <e8> f2 63 0f f6 65 8b 05 9b c9 37 08 85 c0 74 06 5b e9 01 4d 00 00
RSP: 0018:ffffc9000f767ca0 EFLAGS: 00000206
RAX: 0000000007e9db2b RBX: ffff888030ec2500 RCX: ffffffff81c707ef
RDX: 0000000000000000 RSI: ffffffff8dacdf23 RDI: 0000000000000001
RBP: ffff888030ec2900 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff9088b4d7 R11: ffff888077882ff0 R12: 0000000000000000
R13: 0000000000000021 R14: 0000000000000400 R15: ffff888030ec2500
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 get_signal+0x1e6a/0x26d0 kernel/signal.c:3037
 arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd8dc38f749
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:00007fff60344398 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007fd8dc5e7da0 RCX: 00007fd8dc38f749
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fd8dc5e7da0 R08: 0000000000000208 R09: 0000001e6034468f
R10: 00007fd8dc5e7cb0 R11: 0000000000000246 R12: 0000000000078247
R13: 00007fd8dc5e6090 R14: ffffffffffffffff R15: 00007fff603444b0
 </TASK>
----------------
Code disassembly (best guess):
   0:	90                   	nop
   1:	f3 0f 1e fa          	endbr64
   5:	53                   	push   %rbx
   6:	48 8b 74 24 08       	mov    0x8(%rsp),%rsi
   b:	48 89 fb             	mov    %rdi,%rbx
   e:	48 83 c7 18          	add    $0x18,%rdi
  12:	e8 2a 0e 1f f6       	call   0xf61f0e41
  17:	48 89 df             	mov    %rbx,%rdi
  1a:	e8 e2 60 1f f6       	call   0xf61f6101
  1f:	e8 5d 22 4c f6       	call   0xf64c2281
  24:	fb                   	sti
  25:	bf 01 00 00 00       	mov    $0x1,%edi
* 2a:	e8 f2 63 0f f6       	call   0xf60f6421 <-- trapping instruction
  2f:	65 8b 05 9b c9 37 08 	mov    %gs:0x837c99b(%rip),%eax        # 0x837c9d1
  36:	85 c0                	test   %eax,%eax
  38:	74 06                	je     0x40
  3a:	5b                   	pop    %rbx
  3b:	e9 01 4d 00 00       	jmp    0x4d41