Oops: divide error: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 28292 Comm: syz.0.6583 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+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: ffff888056534680 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff888024146000 RBP: 0000000000000002 R08: 0000000000000000 R09: 1ffff11004828c00 R10: dffffc0000000000 R11: ffffffff88b4faa0 R12: dffffc0000000000 R13: ffff888056534638 R14: 0000000000000000 R15: ffff888056534600 FS: 00007f2e99a1d6c0(0000) GS:ffff88812613e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000000bd038 CR3: 000000005645a000 CR4: 0000000000350ef0 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+0xb6/0xe0 arch/x86/kernel/irq.c:318 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688 RIP: 0010:_copy_from_user+0x9b/0xb0 lib/usercopy.c:18 Code: d9 4c 89 fe f3 a4 0f 1f 00 49 89 cf 0f 01 ca 31 ff 48 89 ce e8 e6 97 36 fd 4d 85 ff 75 16 e8 fc 92 36 fd 45 31 ff 4c 89 f8 5b <41> 5e 41 5f e9 07 d0 86 fc cc e8 e6 92 36 fd eb 8d 0f 1f 40 00 90 RSP: 0018:ffffc90004497a28 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc90004497aa0 RCX: 0000000000080000 RDX: ffffc9001d856000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc90004497c30 R08: ffffc90004497ad7 R09: 1ffff92000892f5a R10: dffffc0000000000 R11: fffff52000892f5b R12: 0000000000000002 R13: dffffc0000000000 R14: ffffc90004497aa0 R15: 0000000000000000 copy_from_user include/linux/uaccess.h:212 [inline] copy_msghdr_from_user net/socket.c:2560 [inline] recvmsg_copy_msghdr net/socket.c:2816 [inline] ___sys_recvmsg+0x12e/0x510 net/socket.c:2888 do_recvmmsg+0x307/0x770 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+0x190/0x240 net/socket.c:3077 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: 0033:0x7f2e98b8efc9 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:00007f2e99a1d038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f2e98de6090 RCX: 00007f2e98b8efc9 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000007 RBP: 00007f2e98c11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2e98de6128 R14: 00007f2e98de6090 R15: 00007ffdae2504f8 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: ffff888056534680 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff888024146000 RBP: 0000000000000002 R08: 0000000000000000 R09: 1ffff11004828c00 R10: dffffc0000000000 R11: ffffffff88b4faa0 R12: dffffc0000000000 R13: ffff888056534638 R14: 0000000000000000 R15: ffff888056534600 FS: 00007f2e99a1d6c0(0000) GS:ffff88812613e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000000bd038 CR3: 000000005645a000 CR4: 0000000000350ef0 ---------------- 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