diff options
| author | Gerd Hoffmann <kraxel@redhat.com> | 2018-03-09 15:37:04 +0100 |
|---|---|---|
| committer | Gerd Hoffmann <kraxel@redhat.com> | 2018-03-12 11:45:21 +0100 |
| commit | 7cdc61becd095b64a786b2625f321624e7111f3d (patch) | |
| tree | 860a198e9e4e4c3833c05d1a48feb04f1e7888bb /hw/display | |
| parent | e4ae62b802cec437f877f2cadc4ef059cc0eca76 (diff) | |
vga: fix region calculation
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
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
Diffstat (limited to 'hw/display')
| -rw-r--r-- | hw/display/vga.c | 2 |
1 files changed, 2 insertions, 0 deletions
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; |