display/qxl-render: fix race condition in qxl_cursor (CVE-2021-4207)

Avoid fetching 'width' and 'height' a second time to prevent possible
race condition. Refer to security advisory
https://starlabs.sg/advisories/22-4207/ for more information.

Fixes: CVE-2021-4207
Signed-off-by: Mauro Matteo Cascella <mcascell@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220407081106.343235-1-mcascell@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Mauro Matteo Cascella 2022-04-07 10:11:06 +02:00 committed by Gerd Hoffmann
parent 95a3fcc748
commit 9569f5cb5b
1 changed files with 1 additions and 1 deletions

View File

@ -266,7 +266,7 @@ static QEMUCursor *qxl_cursor(PCIQXLDevice *qxl, QXLCursor *cursor,
}
break;
case SPICE_CURSOR_TYPE_ALPHA:
size = sizeof(uint32_t) * cursor->header.width * cursor->header.height;
size = sizeof(uint32_t) * c->width * c->height;
qxl_unpack_chunks(c->data, size, qxl, &cursor->chunk, group_id);
if (qxl->debug > 2) {
cursor_print_ascii_art(c, "qxl/alpha");