From: Prasad J Pandit <p...@fedoraproject.org> 'dst' pointer could exceed vga vram size when writing to the cirrus memory area; it'd lead to an OOB access issue. Add check to avoid it.
Reported-by: Niu Guoxiang <niuguoxi...@huawei.com> Signed-off-by: Prasad J Pandit <p...@fedoraproject.org> --- hw/display/cirrus_vga.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) Update: fixed coding style error, add space around '<<' operator. diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c index afc290ab91..9f1f856679 100644 --- a/hw/display/cirrus_vga.c +++ b/hw/display/cirrus_vga.c @@ -2047,8 +2047,11 @@ static void cirrus_mem_writeb_mode4and5_8bpp(CirrusVGAState * s, } val <<= 1; dst++; + if (dst >= s->vga.vram_ptr + s->vga.vram_size) { + break; + } } - memory_region_set_dirty(&s->vga.vram, offset, 8); + memory_region_set_dirty(&s->vga.vram, offset, x); } static void cirrus_mem_writeb_mode4and5_16bpp(CirrusVGAState * s, @@ -2071,8 +2074,11 @@ static void cirrus_mem_writeb_mode4and5_16bpp(CirrusVGAState * s, } val <<= 1; dst += 2; + if (dst >= s->vga.vram_ptr + s->vga.vram_size) { + break; + } } - memory_region_set_dirty(&s->vga.vram, offset, 16); + memory_region_set_dirty(&s->vga.vram, offset, x << 1); } /*************************************** -- 2.13.6