matroskademux: Avoid integer-overflow resulting in heap corruption in WavPack header...

blocksize + WAVPACK4_HEADER_SIZE might overflow gsize, which then
results in allocating a very small buffer. Into that buffer blocksize
data is memcpy'd later which then causes out of bound writes and can
potentially lead to anything from crashes to remote code execution.

Thanks to Adam Doupe for analyzing and reporting the issue.

CVE: CVE-2022-1920

https://gstreamer.freedesktop.org/security/sa-2022-0004.html

Fixes https://gitlab.freedesktop.org/gstreamer/gstreamer/-/issues/1226

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2612>

diff --git a/subprojects/gst-plugins-good/gst/matroska/matroska-demux.c b/subprojects/gst-plugins-good/gst/matroska/matroska-demux.c
index 64cc6be..01d754c 100644 (file)
--- a/subprojects/gst-plugins-good/gst/matroska/matroska-demux.c
+++ b/subprojects/gst-plugins-good/gst/matroska/matroska-demux.c
@@ -3933,7 +3933,8 @@ gst_matroska_demux_add_wvpk_header (GstElement * element,
   } else {
     guint8 *outdata = NULL;
     gsize buf_size, size;
-    guint32 block_samples, flags, crc, blocksize;
+    guint32 block_samples, flags, crc;
+    gsize blocksize;
     GstAdapter *adapter;
 
     adapter = gst_adapter_new ();
@@ -3974,6 +3975,13 @@ gst_matroska_demux_add_wvpk_header (GstElement * element,
         return GST_FLOW_ERROR;
       }
 
+      if (blocksize > G_MAXSIZE - WAVPACK4_HEADER_SIZE) {
+        GST_ERROR_OBJECT (element, "Too big wavpack buffer");
+        gst_buffer_unmap (*buf, &map);
+        g_object_unref (adapter);
+        return GST_FLOW_ERROR;
+      }
+
       g_assert (newbuf == NULL);
 
       newbuf =