| Message ID | 20180312105941.15439-2-kraxel@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 3/12/2018 5:59 AM, Gerd Hoffmann wrote: > Typically the scanline length and the line offset are identical. But > in case they are not our calculation for region_end is incorrect. Using > line_offset is fine for all scanlines, except the last one where we have > to use the actual scanline length. > > Fixes: CVE-2018-7550 This doesn't appear to be the correct CVE number. https://nvd.nist.gov/vuln/detail/CVE-2018-7550 ..please confirm.. Thanks, -Mark > Reported-by: Ross Lagerwall <ross.lagerwall@citrix.com> > Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> > Reviewed-by: Prasad J Pandit <pjp@fedoraproject.org> > Tested-by: Ross Lagerwall <ross.lagerwall@citrix.com> > Message-id: 20180309143704.13420-1-kraxel@redhat.com > --- > hw/display/vga.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/hw/display/vga.c b/hw/display/vga.c > index 28f298b342..72181330b8 100644 > --- a/hw/display/vga.c > +++ b/hw/display/vga.c > @@ -1483,6 +1483,8 @@ static void vga_draw_graphic(VGACommonState *s, int full_update) > > region_start = (s->start_addr * 4); > region_end = region_start + (ram_addr_t)s->line_offset * height; > + region_end += width * s->get_bpp(s) / 8; /* scanline length */ > + region_end -= s->line_offset; > if (region_end > s->vbe_size) { > /* wraps around (can happen with cirrus vbe modes) */ > region_start = 0; >
diff --git a/hw/display/vga.c b/hw/display/vga.c index 28f298b342..72181330b8 100644 --- a/hw/display/vga.c +++ b/hw/display/vga.c @@ -1483,6 +1483,8 @@ static void vga_draw_graphic(VGACommonState *s, int full_update) region_start = (s->start_addr * 4); region_end = region_start + (ram_addr_t)s->line_offset * height; + region_end += width * s->get_bpp(s) / 8; /* scanline length */ + region_end -= s->line_offset; if (region_end > s->vbe_size) { /* wraps around (can happen with cirrus vbe modes) */ region_start = 0;