syzbot

Oops: divide error: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 11660 Comm: irq/7-comedi_pa Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:comedi_inc_scan_progress+0x1a4/0x430 drivers/comedi/drivers.c:563
Code: b6 0c 19 84 c9 0f 85 bd 01 00 00 03 45 2c 4c 8d a5 80 00 00 00 4c 89 e1 48 c1 e9 03 0f b6 0c 19 84 c9 0f 85 cc 01 00 00 31 d2 <41> f7 34 24 41 89 17 45 89 ec eb 0f e8 3b e1 55 f9 48 bb 00 00 00
RSP: 0018:ffffc9000512fac0 EFLAGS: 00010246
RAX: 0000000000000001 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88804a72b400 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed10089f8001 R12: ffff88804a72b480
R13: 0000000000000002 R14: 0000000000000000 R15: ffff88804a72b42c
FS:  0000000000000000(0000) GS:ffff8881268bc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f990ba056c0 CR3: 0000000028634000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 comedi_buf_write_samples+0x373/0x5a0 drivers/comedi/comedi_buf.c:603
 parport_interrupt+0xf3/0x150 drivers/comedi/drivers/comedi_parport.c:218
 irq_thread_fn kernel/irq/manage.c:1131 [inline]
 irq_forced_thread_fn+0x98/0x120 kernel/irq/manage.c:1153
 irq_thread+0x427/0x690 kernel/irq/manage.c:1256
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:comedi_inc_scan_progress+0x1a4/0x430 drivers/comedi/drivers.c:563
Code: b6 0c 19 84 c9 0f 85 bd 01 00 00 03 45 2c 4c 8d a5 80 00 00 00 4c 89 e1 48 c1 e9 03 0f b6 0c 19 84 c9 0f 85 cc 01 00 00 31 d2 <41> f7 34 24 41 89 17 45 89 ec eb 0f e8 3b e1 55 f9 48 bb 00 00 00
RSP: 0018:ffffc9000512fac0 EFLAGS: 00010246
RAX: 0000000000000001 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88804a72b400 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed10089f8001 R12: ffff88804a72b480
R13: 0000000000000002 R14: 0000000000000000 R15: ffff88804a72b42c
FS:  0000000000000000(0000) GS:ffff8881268bc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f990ba056c0 CR3: 0000000028634000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess):
   0:	b6 0c                	mov    $0xc,%dh
   2:	19 84 c9 0f 85 bd 01 	sbb    %eax,0x1bd850f(%rcx,%rcx,8)
   9:	00 00                	add    %al,(%rax)
   b:	03 45 2c             	add    0x2c(%rbp),%eax
   e:	4c 8d a5 80 00 00 00 	lea    0x80(%rbp),%r12
  15:	4c 89 e1             	mov    %r12,%rcx
  18:	48 c1 e9 03          	shr    $0x3,%rcx
  1c:	0f b6 0c 19          	movzbl (%rcx,%rbx,1),%ecx
  20:	84 c9                	test   %cl,%cl
  22:	0f 85 cc 01 00 00    	jne    0x1f4
  28:	31 d2                	xor    %edx,%edx
* 2a:	41 f7 34 24          	divl   (%r12) <-- trapping instruction
  2e:	41 89 17             	mov    %edx,(%r15)
  31:	45 89 ec             	mov    %r13d,%r12d
  34:	eb 0f                	jmp    0x45
  36:	e8 3b e1 55 f9       	call   0xf955e176
  3b:	48                   	rex.W
  3c:	bb                   	.byte 0xbb
  3d:	00 00                	add    %al,(%rax)