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gdk-pixbuf2/SOURCES/gif-check-for-overflow.patch

62 lines
3.1 KiB

From 6976bdc8ee9dd2c2954f91066f7b0f643769a379 Mon Sep 17 00:00:00 2001
From: Robert Ancell <robert.ancell@canonical.com>
Date: Thu, 3 Jun 2021 11:05:56 +1200
Subject: [PATCH] gif: Check for overflow when compositing or clearing frames.
Fixes: #190
Similar to fix in 086e8adf4cc352cd11572f96066b001b545f354e
---
gdk-pixbuf/io-gif-animation.c | 21 +++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)
diff --git a/gdk-pixbuf/io-gif-animation.c b/gdk-pixbuf/io-gif-animation.c
index 8335cdd76..71d9265e6 100644
--- a/gdk-pixbuf/io-gif-animation.c
+++ b/gdk-pixbuf/io-gif-animation.c
@@ -369,7 +369,7 @@ composite_frame (GdkPixbufGifAnim *anim, GdkPixbufFrame *frame)
for (i = 0; i < n_indexes; i++) {
guint8 index = index_buffer[i];
guint x, y;
- int offset;
+ gsize offset;
if (index == frame->transparent_index)
continue;
@@ -379,11 +379,13 @@ composite_frame (GdkPixbufGifAnim *anim, GdkPixbufFrame *frame)
if (x >= anim->width || y >= anim->height)
continue;
- offset = y * gdk_pixbuf_get_rowstride (anim->last_frame_data) + x * 4;
- pixels[offset + 0] = frame->color_map[index * 3 + 0];
- pixels[offset + 1] = frame->color_map[index * 3 + 1];
- pixels[offset + 2] = frame->color_map[index * 3 + 2];
- pixels[offset + 3] = 255;
+ if (g_size_checked_mul (&offset, gdk_pixbuf_get_rowstride (anim->last_frame_data), y) &&
+ g_size_checked_add (&offset, offset, x * 4)) {
+ pixels[offset + 0] = frame->color_map[index * 3 + 0];
+ pixels[offset + 1] = frame->color_map[index * 3 + 1];
+ pixels[offset + 2] = frame->color_map[index * 3 + 2];
+ pixels[offset + 3] = 255;
+ }
}
out:
@@ -448,8 +450,11 @@ gdk_pixbuf_gif_anim_iter_get_pixbuf (GdkPixbufAnimationIter *anim_iter)
x_end = MIN (anim->last_frame->x_offset + anim->last_frame->width, anim->width);
y_end = MIN (anim->last_frame->y_offset + anim->last_frame->height, anim->height);
for (y = anim->last_frame->y_offset; y < y_end; y++) {
- guchar *line = pixels + y * gdk_pixbuf_get_rowstride (anim->last_frame_data) + anim->last_frame->x_offset * 4;
- memset (line, 0, (x_end - anim->last_frame->x_offset) * 4);
+ gsize offset;
+ if (g_size_checked_mul (&offset, gdk_pixbuf_get_rowstride (anim->last_frame_data), y) &&
+ g_size_checked_add (&offset, offset, anim->last_frame->x_offset * 4)) {
+ memset (pixels + offset, 0, (x_end - anim->last_frame->x_offset) * 4);
+ }
}
break;
case GDK_PIXBUF_FRAME_REVERT:
--
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