rmdemux: Make sure we have enough data available when parsing audio/video packets

Otherwise there will be out-of-bounds reads and potential crashes.

Thanks to Natalie Silvanovich for reporting.

Fixes https://gitlab.freedesktop.org/gstreamer/gst-plugins-ugly/-/issues/37

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-ugly/-/merge_requests/74>
This commit is contained in:
Sebastian Dröge 2021-03-03 11:05:14 +02:00 committed by Tim-Philipp Müller
parent a9105ad1e1
commit 3aba7d1e62

View file

@ -2223,6 +2223,9 @@ gst_rmdemux_parse_video_packet (GstRMDemux * rmdemux, GstRMDemuxStream * stream,
gst_buffer_map (in, &map, GST_MAP_READ);
if (map.size < offset)
goto not_enough_data;
data = map.data + offset;
size = map.size - offset;
@ -2289,6 +2292,9 @@ gst_rmdemux_parse_video_packet (GstRMDemux * rmdemux, GstRMDemuxStream * stream,
}
GST_DEBUG_OBJECT (rmdemux, "fragment size %d", fragment_size);
if (map.size < (data - map.data) + fragment_size)
goto not_enough_data;
/* get the fragment */
fragment =
gst_buffer_copy_region (in, GST_BUFFER_COPY_ALL, data - map.data,
@ -2437,6 +2443,9 @@ gst_rmdemux_parse_audio_packet (GstRMDemux * rmdemux, GstRMDemuxStream * stream,
GstFlowReturn ret;
GstBuffer *buffer;
if (gst_buffer_get_size (in) < offset)
goto not_enough_data;
buffer = gst_buffer_copy_region (in, GST_BUFFER_COPY_MEMORY, offset, -1);
if (rmdemux->first_ts != -1 && timestamp > rmdemux->first_ts)
@ -2467,9 +2476,19 @@ gst_rmdemux_parse_audio_packet (GstRMDemux * rmdemux, GstRMDemuxStream * stream,
ret = gst_pad_push (stream->pad, buffer);
}
done:
gst_buffer_unref (in);
return ret;
/* ERRORS */
not_enough_data:
{
GST_ELEMENT_WARNING (rmdemux, STREAM, DECODE, ("Skipping bad packet."),
(NULL));
ret = GST_FLOW_OK;
goto done;
}
}
static GstFlowReturn
@ -2490,6 +2509,9 @@ gst_rmdemux_parse_packet (GstRMDemux * rmdemux, GstBuffer * in, guint16 version)
data = map.data;
size = map.size;
if (size < 4 + 6 + 1 + 2)
goto not_enough_data;
/* stream number */
id = RMDEMUX_GUINT16_GET (data);
@ -2525,6 +2547,9 @@ gst_rmdemux_parse_packet (GstRMDemux * rmdemux, GstBuffer * in, guint16 version)
/* version 1 has an extra byte */
if (version == 1) {
if (size < 1)
goto not_enough_data;
data += 1;
size -= 1;
}
@ -2596,6 +2621,16 @@ unknown_stream:
gst_buffer_unref (in);
return GST_FLOW_OK;
}
/* ERRORS */
not_enough_data:
{
GST_ELEMENT_WARNING (rmdemux, STREAM, DECODE, ("Skipping bad packet."),
(NULL));
gst_buffer_unmap (in, &map);
gst_buffer_unref (in);
return GST_FLOW_OK;
}
}
gboolean