syzbot

Oops: divide error: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5193 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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 4b a7 0d f9 48 bb 00 00 00
RSP: 0018:ffffc90000007c78 EFLAGS: 00010046
RAX: 0000000000000001 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff8880539fa800 R08: ffff88804c48a001 R09: 1ffff11009891400
R10: dffffc0000000000 R11: ffffed1009891401 R12: ffff8880539fa880
R13: 0000000000000002 R14: 0000000000000000 R15: ffff8880539fa82c
FS:  00007f973c283880(0000) GS:ffff88812613b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f60d70e5f98 CR3: 00000000531eb000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 comedi_buf_write_samples+0x373/0x5a0 drivers/comedi/comedi_buf.c:603
 das16m1_handler+0x213/0x4b0 drivers/comedi/drivers/das16m1.c:413
 das16m1_interrupt+0xaf/0x180 drivers/comedi/drivers/das16m1.c:470
 __handle_irq_event_percpu+0x295/0xab0 kernel/irq/handle.c:203
 handle_irq_event_percpu kernel/irq/handle.c:240 [inline]
 handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:257
 handle_edge_irq+0x23b/0xa10 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:-1 [inline]
 __common_interrupt+0x141/0x1f0 arch/x86/kernel/irq.c:325
 common_interrupt+0xb6/0xe0 arch/x86/kernel/irq.c:318
 </IRQ>
 <TASK>
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 5b fd d0 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90003bff768 EFLAGS: 00000206
RAX: aa7e809f671f0e00 RBX: 0000000000000000 RCX: aa7e809f671f0e00
RDX: 0000000000000000 RSI: ffffffff8d8f4ebc RDI: ffffffff8bbf0760
RBP: ffffffff82607cec R08: 0000000000000000 R09: ffffffff82607cec
R10: dffffc0000000000 R11: ffffed1004894e79 R12: 0000000000000002
R13: ffffffff8df3d6e0 R14: 0000000000000000 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:867 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
 kernfs_root+0x38/0x230 fs/kernfs/kernfs-internal.h:75
 kernfs_root_is_locked fs/kernfs/kernfs-internal.h:109 [inline]
 kernfs_rcu_name fs/kernfs/kernfs-internal.h:119 [inline]
 kernfs_dop_revalidate+0x365/0x5d0 fs/kernfs/dir.c:1192
 d_revalidate fs/namei.c:929 [inline]
 lookup_fast+0x253/0x5b0 fs/namei.c:-1
 walk_component fs/namei.c:2147 [inline]
 link_path_walk+0x642/0xea0 fs/namei.c:2519
 path_lookupat+0x97/0x430 fs/namei.c:2675
 filename_lookup+0x212/0x570 fs/namei.c:2705
 vfs_statx+0xf8/0x550 fs/stat.c:353
 vfs_fstatat+0x118/0x170 fs/stat.c:375
 __do_sys_newfstatat fs/stat.c:542 [inline]
 __se_sys_newfstatat fs/stat.c:536 [inline]
 __x64_sys_newfstatat+0x116/0x190 fs/stat.c:536
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f973bb11b0a
Code: 48 8b 15 f1 f2 0d 00 f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 41 89 ca b8 06 01 00 00 0f 05 <3d> 00 f0 ff ff 77 07 31 c0 c3 0f 1f 40 00 48 8b 15 b9 f2 0d 00 f7
RSP: 002b:00007ffc05ecdc58 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 00007ffc05ece0f0 RCX: 00007f973bb11b0a
RDX: 00007ffc05ecdc60 RSI: 00007ffc05ece0f0 RDI: 00000000ffffff9c
RBP: 00005616cc3a0910 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc05ecdcf0
R13: 00000000000000fe R14: 00005616a50abbe0 R15: 00007ffc05ece7f0
 </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 4b a7 0d f9 48 bb 00 00 00
RSP: 0018:ffffc90000007c78 EFLAGS: 00010046
RAX: 0000000000000001 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff8880539fa800 R08: ffff88804c48a001 R09: 1ffff11009891400
R10: dffffc0000000000 R11: ffffed1009891401 R12: ffff8880539fa880
R13: 0000000000000002 R14: 0000000000000000 R15: ffff8880539fa82c
FS:  00007f973c283880(0000) GS:ffff88812613b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f60d70e5f98 CR3: 00000000531eb000 CR4: 0000000000350ef0
----------------
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 4b a7 0d f9       	call   0xf90da786
  3b:	48                   	rex.W
  3c:	bb                   	.byte 0xbb
  3d:	00 00                	add    %al,(%rax)