Oops: divide error: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 18525 Comm: syz.1.3163 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:ffffc90000007d20 EFLAGS: 00010046
RAX: 0000000000000001 RBX: ffffc90003484000 RCX: ffffffff88cbbe1f
RDX: 0000000000000000 RSI: ffffffff88c96640 RDI: 0000000000000004
RBP: dffffc0000000000 R08: 0000000000000004 R09: 0000000000000001
R10: 0000000000000001 R11: ffff888025c1083c R12: ffff888025c10800
R13: 0000000000000002 R14: 0000000000000000 R15: ffffffff88cbbd60
FS: 00007f75494c96c0(0000) GS:ffff8881249d9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f59a565d008 CR3: 0000000054225000 CR4: 00000000003526f0
Call Trace:
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
asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688
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: 90 f3 0f 1e fa 53 48 8b 74 24 08 48 89 fb 48 83 c7 18 e8 0a 48 30 f6 48 89 df e8 f2 9b 30 f6 e8 2d 70 5c f6 fb bf 01 00 00 00 b2 a6 20 f6 65 8b 05 eb a5 3b 08 85 c0 74 06 5b e9 51 4d 00 00
RSP: 0018:ffffc90002edf3a0 EFLAGS: 00000202
RAX: 0000000000001ee9 RBX: ffff8880560357c0 RCX: 0000000000000007
RDX: 0000000000000000 RSI: ffffffff8db032d9 RDI: 0000000000000001
RBP: ffff888055e57c80 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff90832dd7 R11: 0000000000000001 R12: 0000000000000000
R13: ffffc90002edf418 R14: 0000000000000001 R15: 0000000000000000
spin_unlock_irq include/linux/spinlock.h:401 [inline]
shmem_add_to_page_cache+0x6ce/0xa70 mm/shmem.c:911
shmem_alloc_and_add_folio+0x668/0xc20 mm/shmem.c:1936
shmem_get_folio_gfp+0x67f/0x1610 mm/shmem.c:2533
shmem_fault+0x1fe/0xa30 mm/shmem.c:2734
__do_fault+0x10d/0x490 mm/memory.c:5280
do_read_fault mm/memory.c:5698 [inline]
do_fault mm/memory.c:5832 [inline]
do_pte_missing+0xf4a/0x3ba0 mm/memory.c:4361
handle_pte_fault mm/memory.c:6177 [inline]
__handle_mm_fault+0x1556/0x2aa0 mm/memory.c:6318
handle_mm_fault+0x589/0xd10 mm/memory.c:6487
faultin_page mm/gup.c:1126 [inline]
__get_user_pages+0x54e/0x3530 mm/gup.c:1428
populate_vma_page_range+0x267/0x3f0 mm/gup.c:1860
__mm_populate+0x1d8/0x380 mm/gup.c:1963
mm_populate include/linux/mm.h:3471 [inline]
vm_mmap_pgoff+0x37f/0x470 mm/util.c:586
ksys_mmap_pgoff+0x7d/0x5c0 mm/mmap.c:604
__do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
__se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
__x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
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: 0033:0x7f754858eec9
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:00007f75494c9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f75487e5fa0 RCX: 00007f754858eec9
RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f7548611f91 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f75487e6038 R14: 00007f75487e5fa0 R15: 00007fffc5bb7088
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: ffffc90003484000 RCX: ffffffff88cbbe1f
RDX: 0000000000000000 RSI: ffffffff88c96640 RDI: 0000000000000004
RBP: dffffc0000000000 R08: 0000000000000004 R09: 0000000000000001
R10: 0000000000000001 R11: ffff888025c1083c R12: ffff888025c10800
R13: 0000000000000002 R14: 0000000000000000 R15: ffffffff88cbbd60
FS: 00007f75494c96c0(0000) GS:ffff8881249d9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f59a565d008 CR3: 0000000054225000 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)