vmsvga: correct bitmap and pixmap size checks

When processing svga command DEFINE_CURSOR in vmsvga_fifo_run,
the computed BITMAP and PIXMAP size are checked against the
'cursor.mask[]' and 'cursor.image[]' array sizes in bytes.
Correct these checks to avoid OOB memory access.

Reported-by: Qinghao Tang <luodalongde@gmail.com>
Reported-by: Li Qiang <liqiang6-s@360.cn>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Message-id: 1473338754-15430-1-git-send-email-ppandit@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Prasad J Pandit 2016-09-08 18:15:54 +05:30 committed by Gerd Hoffmann
parent 7263da7804
commit 167d97a3de

View File

@ -676,11 +676,13 @@ static void vmsvga_fifo_run(struct vmsvga_state_s *s)
cursor.bpp = vmsvga_fifo_read(s);
args = SVGA_BITMAP_SIZE(x, y) + SVGA_PIXMAP_SIZE(x, y, cursor.bpp);
if (cursor.width > 256 ||
cursor.height > 256 ||
cursor.bpp > 32 ||
SVGA_BITMAP_SIZE(x, y) > sizeof cursor.mask ||
SVGA_PIXMAP_SIZE(x, y, cursor.bpp) > sizeof cursor.image) {
if (cursor.width > 256
|| cursor.height > 256
|| cursor.bpp > 32
|| SVGA_BITMAP_SIZE(x, y)
> sizeof(cursor.mask) / sizeof(cursor.mask[0])
|| SVGA_PIXMAP_SIZE(x, y, cursor.bpp)
> sizeof(cursor.image) / sizeof(cursor.image[0])) {
goto badcmd;
}