Harden API and internals against overly large images

Prevents potential integer overflow -> insufficient allocation -> heap overflow scenarios.

src/lib/api.c

@@ -1976,7 +1976,7 @@ imlib_create_image(int width, int height)
    DATA32             *data;
 
    CHECK_CONTEXT(ctx);
-   if ((width <= 0) || (height <= 0))
+   if (!IMAGE_DIMENSIONS_OK(width, height))
       return NULL;
    data = malloc(width * height * sizeof(DATA32));
    if (data)
@@ -2010,7 +2010,7 @@ imlib_create_image_using_data(int width, int height, DATA32 * data)
    CHECK_CONTEXT(ctx);
    CHECK_PARAM_POINTER_RETURN("imlib_create_image_using_data", "data", data,
                               NULL);
-   if ((width <= 0) || (height <= 0))
+   if (!IMAGE_DIMENSIONS_OK(width, height))
       return NULL;
    im = __imlib_CreateImage(width, height, data);
    if (im)
@@ -2039,7 +2039,7 @@ imlib_create_image_using_copied_data(int width, int height, DATA32 * data)
    CHECK_CONTEXT(ctx);
    CHECK_PARAM_POINTER_RETURN("imlib_create_image_using_copied_data", "data",
                               data, NULL);
-   if ((width <= 0) || (height <= 0))
+   if (!IMAGE_DIMENSIONS_OK(width, height))
       return NULL;
    im = __imlib_CreateImage(width, height, NULL);
    if (!im)
@@ -2085,6 +2085,8 @@ imlib_create_image_from_drawable(Pixmap mask, int x, int y, int width,
    char                domask = 0;
 
    CHECK_CONTEXT(ctx);
+   if (!IMAGE_DIMENSIONS_OK(width, height))
+      return NULL;
    if (mask)
      {
         domask = 1;
@@ -2131,6 +2133,8 @@ imlib_create_image_from_ximage(XImage * image, XImage * mask, int x, int y,
    ImlibImage         *im;
 
    CHECK_CONTEXT(ctx);
+   if (!IMAGE_DIMENSIONS_OK(width, height))
+      return NULL;
    im = __imlib_CreateImage(width, height, NULL);
    im->data = malloc(width * height * sizeof(DATA32));
    __imlib_GrabXImageToRGBA(im->data, 0, 0, width, height,
@@ -2181,6 +2185,10 @@ imlib_create_scaled_image_from_drawable(Pixmap mask, int source_x,
    Pixmap              p, m;
 
    CHECK_CONTEXT(ctx);
+   if (!IMAGE_DIMENSIONS_OK(source_width, source_height))
+      return NULL;
+   if (!IMAGE_DIMENSIONS_OK(destination_width, destination_height))
+      return NULL;
    if ((mask) || (get_mask_from_shape))
       domask = 1;
    p = XCreatePixmap(ctx->display, ctx->drawable, destination_width,
@@ -2375,6 +2383,10 @@ imlib_clone_image(void)
       im_old->loader->load(im_old, NULL, 0, 1);
    if (!(im_old->data))
       return NULL;
+   /* Note: below check should've ensured by original image allocation,
+    * but better safe than sorry. */
+   if (!IMAGE_DIMENSIONS_OK(im_old->w, im_old->h))
+      return NULL;
    im = __imlib_CreateImage(im_old->w, im_old->h, NULL);
    if (!(im))
       return NULL;
@@ -2423,6 +2435,8 @@ imlib_create_cropped_image(int x, int y, int width, int height)
    CHECK_CONTEXT(ctx);
    CHECK_PARAM_POINTER_RETURN("imlib_create_cropped_image", "image",
                               ctx->image, NULL);
+   if (!IMAGE_DIMENSIONS_OK(abs(width), abs(height)))
+      return NULL;
    CAST_IMAGE(im_old, ctx->image);
    if ((!(im_old->data)) && (im_old->loader) && (im_old->loader->load))
       im_old->loader->load(im_old, NULL, 0, 1);
@@ -2479,6 +2493,8 @@ imlib_create_cropped_scaled_image(int source_x, int source_y,
    CHECK_CONTEXT(ctx);
    CHECK_PARAM_POINTER_RETURN("imlib_create_cropped_scaled_image", "image",
                               ctx->image, NULL);
+   if (!IMAGE_DIMENSIONS_OK(abs(destination_width), abs(destination_height)))
+      return NULL;
    CAST_IMAGE(im_old, ctx->image);
    if ((!(im_old->data)) && (im_old->loader) && (im_old->loader->load))
       im_old->loader->load(im_old, NULL, 0, 1);
@@ -4681,6 +4697,9 @@ imlib_create_rotated_image(double angle)
    dx = (int)(cos(angle) * _ROTATE_PREC_MAX);
    dy = -(int)(sin(angle) * _ROTATE_PREC_MAX);
 
+   if (!IMAGE_DIMENSIONS_OK(sz, sz))
+      return NULL;
+
    im = __imlib_CreateImage(sz, sz, NULL);
    im->data = calloc(sz * sz, sizeof(DATA32));
    if (!(im->data))

src/lib/font_draw.c

@@ -81,10 +81,11 @@ __imlib_render_str(ImlibImage * im, ImlibFont * fn, int drx, int dry,
    __imlib_font_query_advance(fn, text, &w, NULL);
    h = __imlib_font_max_ascent_get(fn) - __imlib_font_max_descent_get(fn);
 
-   data = malloc(w * h * sizeof(DATA32));
+   if (!IMAGE_DIMENSIONS_OK(w, h))
+      return;
+   data = calloc(w * h, sizeof(DATA32));
    if (!data)
       return;
-   memset(data, 0, w * h * sizeof(DATA32));
    /* TODO check if this is the right way of rendering. Esp for huge sizes */
    im2 = __imlib_CreateImage(w, h, data);
    if (!im2)

src/lib/rend.c

@@ -580,6 +580,9 @@ __imlib_RenderImageSkewed(Display * d, ImlibImage * im, Drawable w, Drawable m,
         dy1 = 0;
      }
 
+   if (!IMAGE_DIMENSIONS_OK(dw, dh))
+      return;
+
    __imlib_GetContext(d, v, cm, depth);
 
    back = __imlib_CreateImage(dw, dh, NULL);