Oops: divide error: 0000 [#1] SMP KASAN PTI CPU: 0 UID: 0 PID: 8976 Comm: syz.0.874 Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:comedi_buf_munge drivers/comedi/comedi_buf.c:347 [inline] RIP: 0010:comedi_buf_write_free+0x3c8/0x7e0 drivers/comedi/comedi_buf.c:391 Code: 41 03 45 00 48 8b 4c 24 78 42 0f b6 0c 21 84 c9 4c 8b bc 24 90 00 00 00 44 8b 74 24 54 0f 85 02 01 00 00 31 d2 48 8b 4c 24 30 31 41 89 55 00 48 8b 44 24 70 42 0f b6 04 20 84 c0 0f 85 09 01 RSP: 0018:ffffc90000007bd8 EFLAGS: 00010046 RAX: 0000000000000001 RBX: dffffc0000000000 RCX: ffff888064372c80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8880592a4000 RBP: 0000000000000002 R08: 0000000000000000 R09: 00000000000000ff R10: dffffc0000000000 R11: ffffffff88f35200 R12: dffffc0000000000 R13: ffff888064372c38 R14: 0000000000000000 R15: ffff888064372c00 FS: 00007f4444dd96c0(0000) GS:ffff8881257ab000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3e7ea1 CR3: 0000000066488000 CR4: 00000000003526f0 Call Trace: comedi_buf_write_samples+0x369/0x5a0 drivers/comedi/comedi_buf.c:602 das16m1_handler+0x213/0x4b0 drivers/comedi/drivers/das16m1.c:413 das16m1_interrupt+0xaf/0x180 drivers/comedi/drivers/das16m1.c:470 __handle_irq_event_percpu+0x28c/0x980 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:210 handle_edge_irq+0x267/0x9e0 kernel/irq/chip.c:797 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:266 [inline] __common_interrupt+0x143/0x250 arch/x86/kernel/irq.c:292 common_interrupt+0xb6/0xe0 arch/x86/kernel/irq.c:285 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+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 7b 98 45 f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 e3 46 0e f6 65 8b 05 4c 43 65 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc90015e2f9a0 EFLAGS: 00000206 RAX: c08e1d9cb0222f00 RBX: 0000000000000a02 RCX: c08e1d9cb0222f00 RDX: 0000000000000006 RSI: ffffffff8dc6a0fe RDI: 0000000000000001 RBP: ffffc90015e2fa30 R08: ffffffff8fe3cf37 R09: 1ffffffff1fc79e6 R10: dffffc0000000000 R11: fffffbfff1fc79e7 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffffffff9a2700c0 R15: 1ffff92002bc5f34 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:1198 [inline] serial8250_config_port+0x1451/0x5370 drivers/tty/serial/8250/8250_port.c:3137 univ8250_config_port+0x3d4/0x9a0 drivers/tty/serial/8250/8250_rsa.c:70 uart_do_autoconfig drivers/tty/serial/serial_core.c:1183 [inline] uart_ioctl+0x1354/0x19f0 drivers/tty/serial/serial_core.c:1588 tty_ioctl+0x926/0xde0 drivers/tty/tty_io.c:2792 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4443f8e9a9 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:00007f4444dd9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f44441b6080 RCX: 00007f4443f8e9a9 RDX: 0000000000000000 RSI: 0000000000005453 RDI: 000000000000000c RBP: 00007f4444010d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f44441b6080 R15: 00007ffdf0d0b598 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:comedi_buf_munge drivers/comedi/comedi_buf.c:347 [inline] RIP: 0010:comedi_buf_write_free+0x3c8/0x7e0 drivers/comedi/comedi_buf.c:391 Code: 41 03 45 00 48 8b 4c 24 78 42 0f b6 0c 21 84 c9 4c 8b bc 24 90 00 00 00 44 8b 74 24 54 0f 85 02 01 00 00 31 d2 48 8b 4c 24 30 31 41 89 55 00 48 8b 44 24 70 42 0f b6 04 20 84 c0 0f 85 09 01 RSP: 0018:ffffc90000007bd8 EFLAGS: 00010046 RAX: 0000000000000001 RBX: dffffc0000000000 RCX: ffff888064372c80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8880592a4000 RBP: 0000000000000002 R08: 0000000000000000 R09: 00000000000000ff R10: dffffc0000000000 R11: ffffffff88f35200 R12: dffffc0000000000 R13: ffff888064372c38 R14: 0000000000000000 R15: ffff888064372c00 FS: 00007f4444dd96c0(0000) GS:ffff8881257ab000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3e7ea1 CR3: 0000000066488000 CR4: 00000000003526f0 ---------------- Code disassembly (best guess): 0: 41 03 45 00 add 0x0(%r13),%eax 4: 48 8b 4c 24 78 mov 0x78(%rsp),%rcx 9: 42 0f b6 0c 21 movzbl (%rcx,%r12,1),%ecx e: 84 c9 test %cl,%cl 10: 4c 8b bc 24 90 00 00 mov 0x90(%rsp),%r15 17: 00 18: 44 8b 74 24 54 mov 0x54(%rsp),%r14d 1d: 0f 85 02 01 00 00 jne 0x125 23: 31 d2 xor %edx,%edx 25: 48 8b 4c 24 30 mov 0x30(%rsp),%rcx * 2a: f7 31 divl (%rcx) <-- trapping instruction 2c: 41 89 55 00 mov %edx,0x0(%r13) 30: 48 8b 44 24 70 mov 0x70(%rsp),%rax 35: 42 0f b6 04 20 movzbl (%rax,%r12,1),%eax 3a: 84 c0 test %al,%al 3c: 0f .byte 0xf 3d: 85 09 test %ecx,(%rcx) 3f: 01 .byte 0x1