Re: [libvirt] [Qemu-devel] [PATCH 2/3] adlib: mark as insecure and deprecated.

On 25/10/2018 10:52, Gerd Hoffmann wrote:

We have a lovely, guest-triggerable buffer overflow in opl2 emulation.

Reproducer: outw(0xff60, 0x220); outw(0x1020, 0x220); outw(0xffb0, 0x220); Result: Will overflow FM_OPL->AR_TABLE[] (see hw/audio/fmopl.[ch])

I am dumb and I don't understand. In set_ar_dr you get v = 0xff ar = 15 dr = 15 and OPL->AR_TABLE[60] is accessed. The size of the array is 75, which seems to be actually 14 more than required. Likewise OPL->DR_TABLE[60] is accessed. The next accesses use SLOT->ksr which is 0 so it's fine too. Paolo