From 7ed446dca9454dd66a0180823f57a34bc01845a4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <sebastian@centricular.com>
Date: Tue, 13 Jun 2023 14:23:47 +0300
Subject: [PATCH 1/2] dvdspu: Make sure enough data is allocated for the
 available data

If the size read from the stream is smaller than the currently available
data then the size is bogus and the data should simply be discarded.

Fixes ZDI-CAN-20994
Fixes https://gitlab.freedesktop.org/gstreamer/gstreamer/-/issues/2660

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4896>
---
 gst/dvdspu/gstspu-pgs.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/gst/dvdspu/gstspu-pgs.c b/gst/dvdspu/gstspu-pgs.c
index e609a284df9..e29f4f18826 100644
--- a/gst/dvdspu/gstspu-pgs.c
+++ b/gst/dvdspu/gstspu-pgs.c
@@ -593,6 +593,9 @@ parse_set_object_data (GstDVDSpu * dvdspu, guint8 type, guint8 * payload,
     obj->rle_data_size = GST_READ_UINT24_BE (payload);
     payload += 3;
 
+    if (end - payload > obj->rle_data_size)
+      return 0;
+
     PGS_DUMP ("%d bytes of RLE data, of %d bytes total.\n",
         (int) (end - payload), obj->rle_data_size);
 
-- 
GitLab


From 0dabf0eb00723a26b88e13dcb3030744e84569da Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <sebastian@centricular.com>
Date: Tue, 13 Jun 2023 14:25:04 +0300
Subject: [PATCH 2/2] dvdspu: Avoid integer overflow when checking if enough
 data is available

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4896>
---
 subprojects/gst-plugins-bad/gst/dvdspu/gstspu-pgs.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gst/dvdspu/gstspu-pgs.c b/gst/dvdspu/gstspu-pgs.c
index e29f4f18826..49db6d13d8b 100644
--- a/gst/dvdspu/gstspu-pgs.c
+++ b/gst/dvdspu/gstspu-pgs.c
@@ -607,7 +607,8 @@ parse_set_object_data (GstDVDSpu * dvdspu, guint8 type, guint8 * payload,
     PGS_DUMP ("%d bytes of additional RLE data\n", (int) (end - payload));
     /* Check that the data chunk is for this object version, and fits in the buffer */
     if (obj->rle_data_ver == obj_ver &&
-        obj->rle_data_used + end - payload <= obj->rle_data_size) {
+        end - payload <= obj->rle_data_size &&
+        obj->rle_data_used <= obj->rle_data_size - (end - payload)) {
 
       memcpy (obj->rle_data + obj->rle_data_used, payload, end - payload);
       obj->rle_data_used += end - payload;
-- 
GitLab

