Fix CVE-2021-3497:
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3497
https://gstreamer.freedesktop.org/security/sa-2021-0002.html
Patch copied from upstream source repository:
https://gitlab.freedesktop.org/gstreamer/gst-plugins-good/-/commit/9181191511f9c0be6a89c98b311f49d66bd46dc3?merge_request_iid=903
diff --git a/gst/matroska/matroska-demux.c b/gst/matroska/matroska-demux.c
index 467815986c8c3d86fd8906a0d539b34f67d6693e..0e47ee7b5e25ac3331f30439710ae755235f2a22 100644
--- a/gst/matroska/matroska-demux.c
+++ b/gst/matroska/matroska-demux.c
@@ -3851,6 +3851,12 @@ gst_matroska_demux_add_wvpk_header (GstElement * element,
guint32 block_samples, tmp;
gsize size = gst_buffer_get_size (*buf);
+ if (size < 4) {
+ GST_ERROR_OBJECT (element, "Too small wavpack buffer");
+ gst_buffer_unmap (*buf, &map);
+ return GST_FLOW_ERROR;
+ }
+
gst_buffer_extract (*buf, 0, &tmp, sizeof (guint32));
block_samples = GUINT32_FROM_LE (tmp);
/* we need to reconstruct the header of the wavpack block */
@@ -3858,10 +3864,10 @@ gst_matroska_demux_add_wvpk_header (GstElement * element,
/* -20 because ck_size is the size of the wavpack block -8
* and lace_size is the size of the wavpack block + 12
* (the three guint32 of the header that already are in the buffer) */
- wvh.ck_size = size + sizeof (Wavpack4Header) - 20;
+ wvh.ck_size = size + WAVPACK4_HEADER_SIZE - 20;
/* block_samples, flags and crc are already in the buffer */
- newbuf = gst_buffer_new_allocate (NULL, sizeof (Wavpack4Header) - 12, NULL);
+ newbuf = gst_buffer_new_allocate (NULL, WAVPACK4_HEADER_SIZE - 12, NULL);
gst_buffer_map (newbuf, &outmap, GST_MAP_WRITE);
data = outmap.data;
@@ -3886,9 +3892,11 @@ gst_matroska_demux_add_wvpk_header (GstElement * element,
audiocontext->wvpk_block_index += block_samples;
} else {
guint8 *outdata = NULL;
- guint outpos = 0;
- gsize buf_size, size, out_size = 0;
+ gsize buf_size, size;
guint32 block_samples, flags, crc, blocksize;
+ GstAdapter *adapter;
+
+ adapter = gst_adapter_new ();
gst_buffer_map (*buf, &map, GST_MAP_READ);
buf_data = map.data;
@@ -3897,6 +3905,7 @@ gst_matroska_demux_add_wvpk_header (GstElement * element,
if (buf_size < 4) {
GST_ERROR_OBJECT (element, "Too small wavpack buffer");
gst_buffer_unmap (*buf, &map);
+ g_object_unref (adapter);
return GST_FLOW_ERROR;
}
@@ -3918,59 +3927,57 @@ gst_matroska_demux_add_wvpk_header (GstElement * element,
data += 4;
size -= 4;
- if (blocksize == 0 || size < blocksize)
- break;
-
- g_assert ((newbuf == NULL) == (outdata == NULL));
+ if (blocksize == 0 || size < blocksize) {
+ GST_ERROR_OBJECT (element, "Too small wavpack buffer");
+ gst_buffer_unmap (*buf, &map);
+ g_object_unref (adapter);
+ return GST_FLOW_ERROR;
+ }
- if (newbuf == NULL) {
- out_size = sizeof (Wavpack4Header) + blocksize;
- newbuf = gst_buffer_new_allocate (NULL, out_size, NULL);
+ g_assert (newbuf == NULL);
- gst_buffer_copy_into (newbuf, *buf,
- GST_BUFFER_COPY_TIMESTAMPS | GST_BUFFER_COPY_FLAGS, 0, -1);
+ newbuf =
+ gst_buffer_new_allocate (NULL, WAVPACK4_HEADER_SIZE + blocksize,
+ NULL);
+ gst_buffer_map (newbuf, &outmap, GST_MAP_WRITE);
+ outdata = outmap.data;
+
+ outdata[0] = 'w';
+ outdata[1] = 'v';
+ outdata[2] = 'p';
+ outdata[3] = 'k';
+ outdata += 4;
+
+ GST_WRITE_UINT32_LE (outdata, blocksize + WAVPACK4_HEADER_SIZE - 8);
+ GST_WRITE_UINT16_LE (outdata + 4, wvh.version);
+ GST_WRITE_UINT8 (outdata + 6, wvh.track_no);
+ GST_WRITE_UINT8 (outdata + 7, wvh.index_no);
+ GST_WRITE_UINT32_LE (outdata + 8, wvh.total_samples);
+ GST_WRITE_UINT32_LE (outdata + 12, wvh.block_index);
+ GST_WRITE_UINT32_LE (outdata + 16, block_samples);
+ GST_WRITE_UINT32_LE (outdata + 20, flags);
+ GST_WRITE_UINT32_LE (outdata + 24, crc);
+ outdata += 28;
+
+ memcpy (outdata, data, blocksize);
- outpos = 0;
- gst_buffer_map (newbuf, &outmap, GST_MAP_WRITE);
- outdata = outmap.data;
- } else {
- gst_buffer_unmap (newbuf, &outmap);
- out_size += sizeof (Wavpack4Header) + blocksize;
- gst_buffer_set_size (newbuf, out_size);
- gst_buffer_map (newbuf, &outmap, GST_MAP_WRITE);
- outdata = outmap.data;
- }
+ gst_buffer_unmap (newbuf, &outmap);
+ gst_adapter_push (adapter, newbuf);
+ newbuf = NULL;
- outdata[outpos] = 'w';
- outdata[outpos + 1] = 'v';
- outdata[outpos + 2] = 'p';
- outdata[outpos + 3] = 'k';
- outpos += 4;
-
- GST_WRITE_UINT32_LE (outdata + outpos,
- blocksize + sizeof (Wavpack4Header) - 8);
- GST_WRITE_UINT16_LE (outdata + outpos + 4, wvh.version);
- GST_WRITE_UINT8 (outdata + outpos + 6, wvh.track_no);
- GST_WRITE_UINT8 (outdata + outpos + 7, wvh.index_no);
- GST_WRITE_UINT32_LE (outdata + outpos + 8, wvh.total_samples);
- GST_WRITE_UINT32_LE (outdata + outpos + 12, wvh.block_index);
- GST_WRITE_UINT32_LE (outdata + outpos + 16, block_samples);
- GST_WRITE_UINT32_LE (outdata + outpos + 20, flags);
- GST_WRITE_UINT32_LE (outdata + outpos + 24, crc);
- outpos += 28;
-
- memmove (outdata + outpos, data, blocksize);
- outpos += blocksize;
data += blocksize;
size -= blocksize;
}
gst_buffer_unmap (*buf, &map);
- gst_buffer_unref (*buf);
- if (newbuf)
- gst_buffer_unmap (newbuf, &outmap);
+ newbuf = gst_adapter_take_buffer (adapter, gst_adapter_available (adapter));
+ g_object_unref (adapter);
+ gst_buffer_copy_into (newbuf, *buf,
+ GST_BUFFER_COPY_TIMESTAMPS | GST_BUFFER_COPY_FLAGS, 0, -1);
+ gst_buffer_unref (*buf);
*buf = newbuf;
+
audiocontext->wvpk_block_index += block_samples;
}
diff --git a/gst/matroska/matroska-ids.h b/gst/matroska/matroska-ids.h
index 429213f778063ba0063944ab64ad60373bbce5ee..8d4a685a910ec13100a3c3d156b2412d28ec0522 100644
--- a/gst/matroska/matroska-ids.h
+++ b/gst/matroska/matroska-ids.h
@@ -688,6 +688,8 @@ typedef struct _Wavpack4Header {
guint32 crc; /* crc for actual decoded data */
} Wavpack4Header;
+#define WAVPACK4_HEADER_SIZE (32)
+
typedef enum {
GST_MATROSKA_TRACK_ENCODING_SCOPE_FRAME = (1<<0),
GST_MATROSKA_TRACK_ENCODING_SCOPE_CODEC_DATA = (1<<1),