Oops: divide error: 0000 [#1] SMP KASAN NOPTI
CPU: 1 UID: 0 PID: 15005 Comm: syz.5.2433 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:comedi_buf_munge drivers/comedi/comedi_buf.c:347 [inline]
RIP: 0010:comedi_buf_write_free+0x414/0x720 drivers/comedi/comedi_buf.c:391
Code: 02 00 00 31 d2 f7 74 24 1c 48 8b 54 24 30 48 c1 ea 03 0f b6 14 2a 41 03 44 24 38 84 d2 74 09 80 fa 03 0f 8e 66 02 00 00 31 d2 <41> f7 b4 24 80 00 00 00 48 8b 44 24 48 48 c1 e8 03 41 89 54 24 38
RSP: 0018:ffffc90000a08d20 EFLAGS: 00010046
RAX: 0000000000000001 RBX: ffffc9000342c000 RCX: ffffffff88cacf2f
RDX: 0000000000000000 RSI: ffffffff88c87750 RDI: 0000000000000004
RBP: dffffc0000000000 R08: 0000000000000004 R09: 0000000000000001
R10: 0000000000000001 R11: ffff8880744bea3c R12: ffff8880744bea00
R13: 0000000000000002 R14: 0000000000000000 R15: ffffffff88cace70
FS:  00007fd484d7f6c0(0000) GS:ffff888124add000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000002a000 CR3: 0000000064798000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 comedi_buf_write_samples+0x3fc/0x640 drivers/comedi/comedi_buf.c:602
 das16m1_handler+0x203/0x5a0 drivers/comedi/drivers/das16m1.c:413
 das16m1_interrupt+0xb7/0x1c0 drivers/comedi/drivers/das16m1.c:470
 __handle_irq_event_percpu+0x236/0x920 kernel/irq/handle.c:203
 handle_irq_event_percpu kernel/irq/handle.c:240 [inline]
 handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:257
 handle_edge_irq+0x3ca/0x9e0 kernel/irq/chip.c:855
 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
 handle_irq arch/x86/kernel/irq.c:254 [inline]
 call_irq_handler arch/x86/kernel/irq.c:310 [inline]
 __common_interrupt+0xcd/0x2f0 arch/x86/kernel/irq.c:325
 common_interrupt+0xba/0xe0 arch/x86/kernel/irq.c:318
 </IRQ>
 <TASK>
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 86 73 30 f6 48 89 df e8 6e c7 30 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 <bf> 01 00 00 00 e8 b5 d2 20 f6 65 8b 05 5e 55 3c 08 85 c0 74 16 5b
RSP: 0018:ffffc9000cf0fa58 EFLAGS: 00000246
RAX: 0000000000000006 RBX: ffffffff9ae04320 RCX: 0000000000000006
RDX: 0000000000000000 RSI: ffffffff8db02c74 RDI: ffffffff8bf1d240
RBP: 0000000000000283 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff908329d7 R11: 0000000000000000 R12: ffffffff8f072f20
R13: 0000000000000003 R14: 0000000000000000 R15: 1ffff920019e1f5b
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 uart_port_unlock_irqrestore include/linux/serial_core.h:788 [inline]
 autoconfig drivers/tty/serial/8250/8250_port.c:1199 [inline]
 serial8250_config_port+0x1742/0x5040 drivers/tty/serial/8250/8250_port.c:3083
 univ8250_config_port+0x276/0x3b0 drivers/tty/serial/8250/8250_rsa.c:70
 uart_do_autoconfig drivers/tty/serial/serial_core.c:1174 [inline]
 uart_ioctl+0xfd5/0x3080 drivers/tty/serial/serial_core.c:1570
 tty_ioctl+0x661/0x1680 drivers/tty/tty_io.c:2792
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd483f8eec9
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:00007fd484d7f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fd4841e5fa0 RCX: 00007fd483f8eec9
RDX: 00002000000001c0 RSI: 0000000000005453 RDI: 0000000000000003
RBP: 00007fd484011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd4841e6038 R14: 00007fd4841e5fa0 R15: 00007ffc536f3278
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:comedi_buf_munge drivers/comedi/comedi_buf.c:347 [inline]
RIP: 0010:comedi_buf_write_free+0x414/0x720 drivers/comedi/comedi_buf.c:391
Code: 02 00 00 31 d2 f7 74 24 1c 48 8b 54 24 30 48 c1 ea 03 0f b6 14 2a 41 03 44 24 38 84 d2 74 09 80 fa 03 0f 8e 66 02 00 00 31 d2 <41> f7 b4 24 80 00 00 00 48 8b 44 24 48 48 c1 e8 03 41 89 54 24 38
RSP: 0018:ffffc90000a08d20 EFLAGS: 00010046
RAX: 0000000000000001 RBX: ffffc9000342c000 RCX: ffffffff88cacf2f
RDX: 0000000000000000 RSI: ffffffff88c87750 RDI: 0000000000000004
RBP: dffffc0000000000 R08: 0000000000000004 R09: 0000000000000001
R10: 0000000000000001 R11: ffff8880744bea3c R12: ffff8880744bea00
R13: 0000000000000002 R14: 0000000000000000 R15: ffffffff88cace70
FS:  00007fd484d7f6c0(0000) GS:ffff888124add000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000002a000 CR3: 0000000064798000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	02 00                	add    (%rax),%al
   2:	00 31                	add    %dh,(%rcx)
   4:	d2 f7                	shl    %cl,%bh
   6:	74 24                	je     0x2c
   8:	1c 48                	sbb    $0x48,%al
   a:	8b 54 24 30          	mov    0x30(%rsp),%edx
   e:	48 c1 ea 03          	shr    $0x3,%rdx
  12:	0f b6 14 2a          	movzbl (%rdx,%rbp,1),%edx
  16:	41 03 44 24 38       	add    0x38(%r12),%eax
  1b:	84 d2                	test   %dl,%dl
  1d:	74 09                	je     0x28
  1f:	80 fa 03             	cmp    $0x3,%dl
  22:	0f 8e 66 02 00 00    	jle    0x28e
  28:	31 d2                	xor    %edx,%edx
* 2a:	41 f7 b4 24 80 00 00 	divl   0x80(%r12) <-- trapping instruction
  31:	00
  32:	48 8b 44 24 48       	mov    0x48(%rsp),%rax
  37:	48 c1 e8 03          	shr    $0x3,%rax
  3b:	41 89 54 24 38       	mov    %edx,0x38(%r12)