From ad6012159acf18c6b5c0f4edf037e8c9a2dbc966 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= Date: Wed, 18 May 2022 11:24:37 +0300 Subject: [PATCH] matroskademux: Fix integer overflows in zlib/bz2/etc decompression code Various variables were of smaller types than needed and there were no checks for any overflows when doing additions on the sizes. This is all checked now. In addition the size of the decompressed data is limited to 120MB now as any larger sizes are likely pathological and we can avoid out of memory situations in many cases like this. Also fix a bug where the available output size on the next iteration in the zlib/bz2 decompression code was provided too large and could potentially lead to out of bound writes. Thanks to Adam Doupe for analyzing and reporting the issue. CVE: CVE-2022-1922, CVE-2022-1923, CVE-2022-1924, CVE-2022-1925 https://gstreamer.freedesktop.org/security/sa-2022-0002.html Fixes https://gitlab.freedesktop.org/gstreamer/gstreamer/-/issues/1225 Part-of: CVE: CVE-2022-1922 CVE-2022-1923 CVE-2022-1924 CVE-2022-1925 https://gitlab.freedesktop.org/gstreamer/gstreamer/-/commit/ad6012159acf18c6b5c0f4edf037e8c9a2dbc966 Upstream-Status: Backport Signed-off-by: Chee Yang Lee --- .../gst/matroska/matroska-read-common.c | 76 +++++++++++++++---- 1 file changed, 61 insertions(+), 15 deletions(-) diff --git a/gst/matroska/matroska-read-common.c b/gst/matroska/matroska-read-common.c index eb317644cc5..6fadbba9567 100644 --- a/gst/matroska/matroska-read-common.c +++ b/gst/matroska/matroska-read-common.c @@ -70,6 +70,10 @@ typedef struct gboolean audio_only; } TargetTypeContext; +/* 120MB as maximum decompressed data size. Anything bigger is likely + * pathological, and like this we avoid out of memory situations in many cases + */ +#define MAX_DECOMPRESS_SIZE (120 * 1024 * 1024) static gboolean gst_matroska_decompress_data (GstMatroskaTrackEncoding * enc, @@ -77,19 +81,23 @@ gst_matroska_decompress_data (GstMatroskaTrackEncoding * enc, GstMatroskaTrackCompressionAlgorithm algo) { guint8 *new_data = NULL; - guint new_size = 0; + gsize new_size = 0; guint8 *data = *data_out; - guint size = *size_out; + const gsize size = *size_out; gboolean ret = TRUE; + if (size > G_MAXUINT32) { + GST_WARNING ("too large compressed data buffer."); + ret = FALSE; + goto out; + } + if (algo == GST_MATROSKA_TRACK_COMPRESSION_ALGORITHM_ZLIB) { #ifdef HAVE_ZLIB /* zlib encoded data */ z_stream zstream; - guint orig_size; int result; - orig_size = size; zstream.zalloc = (alloc_func) 0; zstream.zfree = (free_func) 0; zstream.opaque = (voidpf) 0; @@ -99,8 +107,8 @@ gst_matroska_decompress_data (GstMatroskaTrackEncoding * enc, goto out; } zstream.next_in = (Bytef *) data; - zstream.avail_in = orig_size; - new_size = orig_size; + zstream.avail_in = size; + new_size = size; new_data = g_malloc (new_size); zstream.avail_out = new_size; zstream.next_out = (Bytef *) new_data; @@ -114,10 +122,18 @@ gst_matroska_decompress_data (GstMatroskaTrackEncoding * enc, break; } + if (new_size > G_MAXSIZE - 4096 || new_size + 4096 > MAX_DECOMPRESS_SIZE) { + GST_WARNING ("too big decompressed data"); + result = Z_MEM_ERROR; + break; + } + new_size += 4096; new_data = g_realloc (new_data, new_size); zstream.next_out = (Bytef *) (new_data + zstream.total_out); - zstream.avail_out += 4096; + /* avail_out is an unsigned int */ + g_assert (new_size - zstream.total_out <= G_MAXUINT); + zstream.avail_out = new_size - zstream.total_out; } while (zstream.avail_in > 0); if (result != Z_STREAM_END) { @@ -137,13 +153,11 @@ gst_matroska_decompress_data (GstMatroskaTrackEncoding * enc, #ifdef HAVE_BZ2 /* bzip2 encoded data */ bz_stream bzstream; - guint orig_size; int result; bzstream.bzalloc = NULL; bzstream.bzfree = NULL; bzstream.opaque = NULL; - orig_size = size; if (BZ2_bzDecompressInit (&bzstream, 0, 0) != BZ_OK) { GST_WARNING ("bzip2 initialization failed."); @@ -152,8 +166,8 @@ gst_matroska_decompress_data (GstMatroskaTrackEncoding * enc, } bzstream.next_in = (char *) data; - bzstream.avail_in = orig_size; - new_size = orig_size; + bzstream.avail_in = size; + new_size = size; new_data = g_malloc (new_size); bzstream.avail_out = new_size; bzstream.next_out = (char *) new_data; @@ -167,17 +181,31 @@ gst_matroska_decompress_data (GstMatroskaTrackEncoding * enc, break; } + if (new_size > G_MAXSIZE - 4096 || new_size + 4096 > MAX_DECOMPRESS_SIZE) { + GST_WARNING ("too big decompressed data"); + result = BZ_MEM_ERROR; + break; + } + new_size += 4096; new_data = g_realloc (new_data, new_size); - bzstream.next_out = (char *) (new_data + bzstream.total_out_lo32); - bzstream.avail_out += 4096; + bzstream.next_out = + (char *) (new_data + ((guint64) bzstream.total_out_hi32 << 32) + + bzstream.total_out_lo32); + /* avail_out is an unsigned int */ + g_assert (new_size - ((guint64) bzstream.total_out_hi32 << 32) + + bzstream.total_out_lo32 <= G_MAXUINT); + bzstream.avail_out = + new_size - ((guint64) bzstream.total_out_hi32 << 32) + + bzstream.total_out_lo32; } while (bzstream.avail_in > 0); if (result != BZ_STREAM_END) { ret = FALSE; g_free (new_data); } else { - new_size = bzstream.total_out_lo32; + new_size = + ((guint64) bzstream.total_out_hi32 << 32) + bzstream.total_out_lo32; } BZ2_bzDecompressEnd (&bzstream); @@ -189,7 +217,13 @@ gst_matroska_decompress_data (GstMatroskaTrackEncoding * enc, } else if (algo == GST_MATROSKA_TRACK_COMPRESSION_ALGORITHM_LZO1X) { /* lzo encoded data */ int result; - int orig_size, out_size; + gint orig_size, out_size; + + if (size > G_MAXINT) { + GST_WARNING ("too large compressed data buffer."); + ret = FALSE; + goto out; + } orig_size = size; out_size = size; @@ -203,6 +237,11 @@ gst_matroska_decompress_data (GstMatroskaTrackEncoding * enc, result = lzo1x_decode (new_data, &out_size, data, &orig_size); if (orig_size > 0) { + if (new_size > G_MAXINT - 4096 || new_size + 4096 > MAX_DECOMPRESS_SIZE) { + GST_WARNING ("too big decompressed data"); + result = LZO_ERROR; + break; + } new_size += 4096; new_data = g_realloc (new_data, new_size); } @@ -221,6 +260,13 @@ gst_matroska_decompress_data (GstMatroskaTrackEncoding * enc, } else if (algo == GST_MATROSKA_TRACK_COMPRESSION_ALGORITHM_HEADERSTRIP) { /* header stripped encoded data */ if (enc->comp_settings_length > 0) { + if (size > G_MAXSIZE - enc->comp_settings_length + || size + enc->comp_settings_length > MAX_DECOMPRESS_SIZE) { + GST_WARNING ("too big decompressed data"); + ret = FALSE; + goto out; + } + new_data = g_malloc (size + enc->comp_settings_length); new_size = size + enc->comp_settings_length; -- GitLab