syzbot

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WARNING: CPU: 0 PID: 6192 at kernel/rcu/tree_stall.h:1001 rcu_check_gp_start_stall+0x2dc/0x460 kernel/rcu/tree_stall.h:993
Modules linked in:
CPU: 0 PID: 6192 Comm: syz.0.66 Not tainted 6.6.102-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:rcu_check_gp_start_stall+0x2dc/0x460 kernel/rcu/tree_stall.h:1001
Code: ff ff ff 48 c7 c7 80 c4 ee 96 be 04 00 00 00 e8 7a a8 6c 00 48 89 df b8 01 00 00 00 87 05 bc 98 7e 15 85 c0 0f 85 19 ff ff ff <0f> 0b 48 81 ff 40 54 d3 8c 74 47 48 c7 c0 dc bc 4a 8e 48 c1 e8 03
RSP: 0018:ffffc90000007bb8 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffffffff8cd35440 RCX: ffffffff81702bb6
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8cd35440
RBP: ffffc90000007e30 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff2ddd890 R12: 0000000000002904
R13: 1ffff110171c7a6a R14: 0000000000000a02 R15: dffffc0000000000
FS:  00007f482f4b66c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe1b19d9f40 CR3: 0000000060a92000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 rcu_core+0x612/0x1720 kernel/rcu/tree.c:2462
 handle_softirqs+0x280/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
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: 00 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 aa 8f f0 f6 48 89 df e8 c2 61 f1 f6 e8 7d fd 14 f7 fb bf 01 00 00 00 <e8> 12 7a e4 f6 65 8b 05 33 c9 8c 75 85 c0 74 02 5b c3 e8 10 ab 89
RSP: 0018:ffffc90003867c98 EFLAGS: 00000282
RAX: e34bde0237e69600 RBX: ffff8880317dd340 RCX: e34bde0237e69600
RDX: dffffc0000000000 RSI: ffffffff8aaab9c0 RDI: 0000000000000001
RBP: ffff8880317dd5d8 R08: ffffffff8e4a882f R09: 1ffffffff1c95105
R10: dffffc0000000000 R11: fffffbfff1c95106 R12: 1ffff110062fbabb
R13: 0000000000000011 R14: dffffc0000000000 R15: 0000000000000000
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 get_signal+0x11f5/0x1400 kernel/signal.c:2905
 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f482e58ebe9
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:00007f482f4b60e8 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 00007f482e7b5fa8 RCX: 00007f482e58ebe9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f482e7b5fa8
RBP: 00007f482e7b5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f482e7b6038 R14: 00007ffd58b2a4c0 R15: 00007ffd58b2a5a8
 </TASK>
----------------
Code disassembly (best guess):
   0:	00 f3                	add    %dh,%bl
   2:	0f 1e fa             	nop    %edx
   5:	53                   	push   %rbx
   6:	48 89 fb             	mov    %rdi,%rbx
   9:	48 83 c7 18          	add    $0x18,%rdi
   d:	48 8b 74 24 08       	mov    0x8(%rsp),%rsi
  12:	e8 aa 8f f0 f6       	call   0xf6f08fc1
  17:	48 89 df             	mov    %rbx,%rdi
  1a:	e8 c2 61 f1 f6       	call   0xf6f161e1
  1f:	e8 7d fd 14 f7       	call   0xf714fda1
  24:	fb                   	sti
  25:	bf 01 00 00 00       	mov    $0x1,%edi
* 2a:	e8 12 7a e4 f6       	call   0xf6e47a41 <-- trapping instruction
  2f:	65 8b 05 33 c9 8c 75 	mov    %gs:0x758cc933(%rip),%eax        # 0x758cc969
  36:	85 c0                	test   %eax,%eax
  38:	74 02                	je     0x3c
  3a:	5b                   	pop    %rbx
  3b:	c3                   	ret
  3c:	e8                   	.byte 0xe8
  3d:	10                   	.byte 0x10
  3e:	ab                   	stos   %eax,%es:(%rdi)
  3f:	89                   	.byte 0x89