Oops: divide error: 0000 [#1] SMP KASAN PTI CPU: 0 UID: 0 PID: 0 Comm: swapper/0 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+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:ffffc90000007958 EFLAGS: 00010046 RAX: 0000000000000001 RBX: dffffc0000000000 RCX: ffff88802a34ee80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff888066eab000 RBP: 0000000000000002 R08: 0000000000000000 R09: 00000000000000ff R10: dffffc0000000000 R11: ffffffff88fda820 R12: dffffc0000000000 R13: ffff88802a34ee38 R14: 0000000000000000 R15: ffff88802a34ee00 FS: 0000000000000000(0000) GS:ffff8881257a2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000000014a4 CR3: 000000006a606000 CR4: 00000000003526f0 DR0: 0000000000000008 DR1: 0000000000000002 DR2: 0000000000000081 DR3: ffffffffefffff14 DR6: 00000000ffff0ff0 DR7: 0000000000000400 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+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+0x5e/0xe0 arch/x86/kernel/irq.c:318 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688 RIP: 0010:variable_ffs arch/x86/include/asm/bitops.h:312 [inline] RIP: 0010:handle_softirqs+0x1b0/0x870 kernel/softirq.c:610 Code: 89 64 24 30 0f b7 db 48 c7 c7 c0 a4 a9 8b e8 67 8f 08 0a 65 66 c7 05 35 b3 62 11 00 00 e8 08 96 42 00 fb 49 c7 c7 c0 c0 20 8e ff ff ff ff 0f bc c3 41 89 c5 41 ff c5 0f 84 c2 03 00 00 89 5c RSP: 0018:ffffc90000007e40 EFLAGS: 00000286 RAX: 6f2617b038c92d00 RBX: 0000000000000100 RCX: 6f2617b038c92d00 RDX: 0000000000000000 RSI: ffffffff8dc89575 RDI: ffffffff8c053d60 RBP: ffffc90000007f50 R08: ffffffff8fe4db77 R09: 1ffffffff1fc9b6e R10: dffffc0000000000 R11: fffffbfff1fc9b6f R12: 000000000000000a R13: 0000000000000000 R14: dffffc0000000000 R15: ffffffff8e20c0c0 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 8a 1a 00 f3 0f 1e fa fb f4 c8 e6 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8e207d80 EFLAGS: 000002c6 RAX: 6f2617b038c92d00 RBX: ffffffff8196e2b7 RCX: 6f2617b038c92d00 RDX: 0000000000000001 RSI: ffffffff8dc89575 RDI: ffffffff8c053d60 RBP: ffffffff8e207ea8 R08: ffff8880b8632fdb R09: 1ffff110170c65fb R10: dffffc0000000000 R11: ffffed10170c65fc R12: ffffffff8fe4db70 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1c52a38 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e7/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x3ae/0x410 init/main.c:1111 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147 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:ffffc90000007958 EFLAGS: 00010046 RAX: 0000000000000001 RBX: dffffc0000000000 RCX: ffff88802a34ee80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff888066eab000 RBP: 0000000000000002 R08: 0000000000000000 R09: 00000000000000ff R10: dffffc0000000000 R11: ffffffff88fda820 R12: dffffc0000000000 R13: ffff88802a34ee38 R14: 0000000000000000 R15: ffff88802a34ee00 FS: 0000000000000000(0000) GS:ffff8881257a2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000000014a4 CR3: 000000006a606000 CR4: 00000000003526f0 DR0: 0000000000000008 DR1: 0000000000000002 DR2: 0000000000000081 DR3: ffffffffefffff14 DR6: 00000000ffff0ff0 DR7: 0000000000000400 ---------------- 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