Oops: divide error: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 12713 Comm: syz.1.8725 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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:ffffc90000007d20 EFLAGS: 00010046
RAX: 0000000000000001 RBX: ffffc9000318e000 RCX: ffffffff88bc29ef
RDX: 0000000000000000 RSI: ffffffff88b9d210 RDI: 0000000000000004
RBP: dffffc0000000000 R08: 0000000000000004 R09: 0000000000000001
R10: 0000000000000001 R11: ffff888021f5463c R12: ffff888021f54600
R13: 0000000000000002 R14: 0000000000000000 R15: ffffffff88bc2930
FS:  00007fd64745e6c0(0000) GS:ffff888124e85000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000a3030 CR3: 000000007b263000 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+0xd0/0x2f0 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:__scm_recv_common.constprop.0+0x15d/0x520 net/core/scm.c:532
Code: 00 00 fc ff df 48 01 c5 48 c7 45 00 00 00 00 00 c7 45 08 00 00 00 00 48 8b 44 24 78 65 48 2b 05 61 1c 50 0a 0f 85 56 03 00 00 <48> 83 ec 80 89 d8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc e8
RSP: 0018:ffffc900044af700 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9000d559000
RDX: 0000000000080000 RSI: ffffffff8929937e RDI: 0000000000000000
RBP: fffff52000895ee0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffc900044af940
R13: ffffc900044afd98 R14: 0000000000000000 R15: ffff88807ca8a298
 scm_recv_unix+0x99/0x400 net/core/scm.c:547
 __unix_dgram_recvmsg+0x769/0xc30 net/unix/af_unix.c:2680
 unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2700
 sock_recvmsg_nosec net/socket.c:1078 [inline]
 ____sys_recvmsg+0x5f9/0x6b0 net/socket.c:2848
 ___sys_recvmsg+0x114/0x1a0 net/socket.c:2892
 do_recvmmsg+0x2fe/0x750 net/socket.c:2987
 __sys_recvmmsg net/socket.c:3061 [inline]
 __do_sys_recvmmsg net/socket.c:3084 [inline]
 __se_sys_recvmmsg net/socket.c:3077 [inline]
 __x64_sys_recvmmsg+0x22a/0x280 net/socket.c:3077
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd64658eec9
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:00007fd64745e038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fd6467e6090 RCX: 00007fd64658eec9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000005
RBP: 00007fd646611f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd6467e6128 R14: 00007fd6467e6090 R15: 00007ffd13eec7a8
 </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:ffffc90000007d20 EFLAGS: 00010046
RAX: 0000000000000001 RBX: ffffc9000318e000 RCX: ffffffff88bc29ef
RDX: 0000000000000000 RSI: ffffffff88b9d210 RDI: 0000000000000004
RBP: dffffc0000000000 R08: 0000000000000004 R09: 0000000000000001
R10: 0000000000000001 R11: ffff888021f5463c R12: ffff888021f54600
R13: 0000000000000002 R14: 0000000000000000 R15: ffffffff88bc2930
FS:  00007fd64745e6c0(0000) GS:ffff888124e85000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000a3030 CR3: 000000007b263000 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)