Commit fa892e9a authored by Mauro Matteo Cascella's avatar Mauro Matteo Cascella Committed by Gerd Hoffmann
Browse files

ui/cursor: fix integer overflow in cursor_alloc (CVE-2021-4206)

Prevent potential integer overflow by limiting 'width' and 'height' to
512x512. Also change 'datasize' type to size_t. Refer to security
advisory https://starlabs.sg/advisories/22-4206/

 for more information.

Fixes: CVE-2021-4206
Signed-off-by: Mauro Matteo Cascella's avatarMauro Matteo Cascella <mcascell@redhat.com>
Reviewed-by: Marc-André Lureau's avatarMarc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220407081712.345609-1-mcascell@redhat.com>
Signed-off-by: Gerd Hoffmann's avatarGerd Hoffmann <kraxel@redhat.com>
parent 9569f5cb
......@@ -247,6 +247,13 @@ static QEMUCursor *qxl_cursor(PCIQXLDevice *qxl, QXLCursor *cursor,
size_t size;
c = cursor_alloc(cursor->header.width, cursor->header.height);
if (!c) {
qxl_set_guest_bug(qxl, "%s: cursor %ux%u alloc error", __func__,
cursor->header.width, cursor->header.height);
goto fail;
}
c->hot_x = cursor->header.hot_spot_x;
c->hot_y = cursor->header.hot_spot_y;
switch (cursor->header.type) {
......
......@@ -515,6 +515,8 @@ static inline void vmsvga_cursor_define(struct vmsvga_state_s *s,
int i, pixels;
qc = cursor_alloc(c->width, c->height);
assert(qc != NULL);
qc->hot_x = c->hot_x;
qc->hot_y = c->hot_y;
switch (c->bpp) {
......
......@@ -46,6 +46,8 @@ static QEMUCursor *cursor_parse_xpm(const char *xpm[])
/* parse pixel data */
c = cursor_alloc(width, height);
assert(c != NULL);
for (pixel = 0, y = 0; y < height; y++, line++) {
for (x = 0; x < height; x++, pixel++) {
idx = xpm[line][x];
......@@ -91,7 +93,11 @@ QEMUCursor *cursor_builtin_left_ptr(void)
QEMUCursor *cursor_alloc(int width, int height)
{
QEMUCursor *c;
int datasize = width * height * sizeof(uint32_t);
size_t datasize = width * height * sizeof(uint32_t);
if (width > 512 || height > 512) {
return NULL;
}
c = g_malloc0(sizeof(QEMUCursor) + datasize);
c->width = width;
......
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