Subject: [PATCH 3/5] gnu: gst-plugins-bad: Fix an overflow when processing video files.

From: Leo Famulari <[email-masked]>
Date: Sat, 24 Apr 2021 15:14:33 -0400

* gnu/packages/patches/gst-plugins-bad-fix-overflow.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/gstreamer.scm (gst-plugins-bad)[source]: Use it.
---
 gnu/local.mk                                  |   1 +
 gnu/packages/gstreamer.scm                    |   1 +
 .../gst-plugins-bad-fix-overflow.patch        | 263 ++++++++++++++++++
 3 files changed, 265 insertions(+)
 create mode 100644 gnu/packages/patches/gst-plugins-bad-fix-overflow.patch

diff --git a/gnu/local.mk b/gnu/local.mk
index b3e84be598..94d7daf910 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -1170,6 +1170,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/grub-verifiers-Blocklist-fallout-cleanup.patch \
   %D%/packages/patches/gspell-dash-test.patch			\
   %D%/packages/patches/gst-libav-64channels-stack-corruption.patch	\
+  %D%/packages/patches/gst-plugins-bad-fix-overflow.patch	\
   %D%/packages/patches/gst-plugins-good-fix-test.patch		\
   %D%/packages/patches/gst-plugins-good-CVE-2021-3497.patch	\
   %D%/packages/patches/gst-plugins-good-CVE-2021-3498.patch	\
diff --git a/gnu/packages/gstreamer.scm b/gnu/packages/gstreamer.scm
index 81ac0a2f5f..58a02119c6 100644
--- a/gnu/packages/gstreamer.scm
+++ b/gnu/packages/gstreamer.scm
@@ -681,6 +681,7 @@ model to base your own plug-in on, here it is.")
               (method url-fetch)
               (uri (string-append "https://gstreamer.freedesktop.org/src/"
                                   name "/" name "-" version ".tar.xz"))
+              (patches (search-patches "gst-plugins-bad-fix-overflow.patch"))
               (sha256
                (base32
                 "06ildd4rl6cynirv3p00d2ddf5is9svj4i7mkahldzhq24pq5mca"))))
diff --git a/gnu/packages/patches/gst-plugins-bad-fix-overflow.patch b/gnu/packages/patches/gst-plugins-bad-fix-overflow.patch
new file mode 100644
index 0000000000..95ab13db51
--- /dev/null
+++ b/gnu/packages/patches/gst-plugins-bad-fix-overflow.patch
@@ -0,0 +1,263 @@
+Fix an overflow when calculating something for AVC/HEVC videos:
+
+https://security-tracker.debian.org/tracker/TEMP-0000000-C6AAE1
+
+Patch copied from upstream source repository:
+
+https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/commit/0cfbf7ad91c7f121192c8ce135769f8eb276c41d
+From 0cfbf7ad91c7f121192c8ce135769f8eb276c41d Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <[email-masked]>
+Date: Tue, 23 Mar 2021 19:19:14 +0200
+Subject: [PATCH] h2645parser: Catch overflows in AVC/HEVC NAL unit length
+ calculations
+
+Offset and size are stored as 32 bit guint and might overflow when
+adding the nal_length_size, so let's avoid that.
+
+For the size this would happen if the AVC/HEVC NAL unit size happens to
+be stored in 4 bytes and is 4294967292 or higher, which is likely
+corrupted data anyway.
+
+For the offset this is something for the caller of these functions to
+take care of but is unlikely to happen as it would require parsing on a
+>4GB buffer.
+
+Allowing these overflows causes all kinds of follow-up bugs in the
+h2645parse elements, ranging from infinite loops and memory leaks to
+potential memory corruptions.
+
+Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2107>
+---
+ gst-libs/gst/codecparsers/gsth264parser.c | 16 +++++-
+ gst-libs/gst/codecparsers/gsth265parser.c | 16 +++++-
+ tests/check/libs/h264parser.c             | 60 +++++++++++++++++++++++
+ tests/check/libs/h265parser.c             | 60 +++++++++++++++++++++++
+ 4 files changed, 150 insertions(+), 2 deletions(-)
+
+diff --git a/gst-libs/gst/codecparsers/gsth264parser.c b/gst-libs/gst/codecparsers/gsth264parser.c
+index 012f1d0d7..68aa25068 100644
+--- a/gst-libs/gst/codecparsers/gsth264parser.c
++++ b/gst-libs/gst/codecparsers/gsth264parser.c
+@@ -1556,6 +1556,14 @@ gst_h264_parser_identify_nalu_avc (GstH264NalParser * nalparser,
+ 
+   memset (nalu, 0, sizeof (*nalu));
+ 
++  /* Would overflow guint below otherwise: the callers needs to ensure that
++   * this never happens */
++  if (offset > G_MAXUINT32 - nal_length_size) {
++    GST_WARNING ("offset + nal_length_size overflow");
++    nalu->size = 0;
++    return GST_H264_PARSER_BROKEN_DATA;
++  }
++
+   if (size < offset + nal_length_size) {
+     GST_DEBUG ("Can't parse, buffer has too small size %" G_GSIZE_FORMAT
+         ", offset %u", size, offset);
+@@ -1570,7 +1578,13 @@ gst_h264_parser_identify_nalu_avc (GstH264NalParser * nalparser,
+   nalu->sc_offset = offset;
+   nalu->offset = offset + nal_length_size;
+ 
+-  if (size < nalu->size + nal_length_size) {
++  if (nalu->size > G_MAXUINT32 - nal_length_size) {
++    GST_WARNING ("NALU size + nal_length_size overflow");
++    nalu->size = 0;
++    return GST_H264_PARSER_BROKEN_DATA;
++  }
++
++  if (size < (gsize) nalu->size + nal_length_size) {
+     nalu->size = 0;
+ 
+     return GST_H264_PARSER_NO_NAL_END;
+diff --git a/gst-libs/gst/codecparsers/gsth265parser.c b/gst-libs/gst/codecparsers/gsth265parser.c
+index 26e68b276..dc7f27aa9 100644
+--- a/gst-libs/gst/codecparsers/gsth265parser.c
++++ b/gst-libs/gst/codecparsers/gsth265parser.c
+@@ -1531,6 +1531,14 @@ gst_h265_parser_identify_nalu_hevc (GstH265Parser * parser,
+ 
+   memset (nalu, 0, sizeof (*nalu));
+ 
++  /* Would overflow guint below otherwise: the callers needs to ensure that
++   * this never happens */
++  if (offset > G_MAXUINT32 - nal_length_size) {
++    GST_WARNING ("offset + nal_length_size overflow");
++    nalu->size = 0;
++    return GST_H265_PARSER_BROKEN_DATA;
++  }
++
+   if (size < offset + nal_length_size) {
+     GST_DEBUG ("Can't parse, buffer has too small size %" G_GSIZE_FORMAT
+         ", offset %u", size, offset);
+@@ -1545,7 +1553,13 @@ gst_h265_parser_identify_nalu_hevc (GstH265Parser * parser,
+   nalu->sc_offset = offset;
+   nalu->offset = offset + nal_length_size;
+ 
+-  if (size < nalu->size + nal_length_size) {
++  if (nalu->size > G_MAXUINT32 - nal_length_size) {
++    GST_WARNING ("NALU size + nal_length_size overflow");
++    nalu->size = 0;
++    return GST_H265_PARSER_BROKEN_DATA;
++  }
++
++  if (size < (gsize) nalu->size + nal_length_size) {
+     nalu->size = 0;
+ 
+     return GST_H265_PARSER_NO_NAL_END;
+diff --git a/tests/check/libs/h264parser.c b/tests/check/libs/h264parser.c
+index c7c46d9a2..d322dd8db 100644
+--- a/tests/check/libs/h264parser.c
++++ b/tests/check/libs/h264parser.c
+@@ -229,6 +229,65 @@ GST_START_TEST (test_h264_parse_slice_5bytes)
+ 
+ GST_END_TEST;
+ 
++GST_START_TEST (test_h264_parse_identify_nalu_avc)
++{
++  GstH264ParserResult res;
++  GstH264NalUnit nalu;
++  GstH264NalParser *const parser = gst_h264_nal_parser_new ();
++  /* Skip 3 bytes for the start code */
++  const gsize nal_size = sizeof (slice_dpa) - 3;
++  const gsize buf_size = 4 + nal_size;
++  guint8 *buf = g_new (guint8, buf_size);
++
++  memcpy (buf + 4, slice_dpa + 3, nal_size);
++
++  GST_WRITE_UINT16_BE (buf + 2, nal_size);
++  res = gst_h264_parser_identify_nalu_avc (parser, buf, 2, buf_size, 2, &nalu);
++
++  assert_equals_int (res, GST_H264_PARSER_OK);
++  assert_equals_int (nalu.type, GST_H264_NAL_SLICE_DPA);
++  assert_equals_int (nalu.offset, 4);
++  assert_equals_int (nalu.size, nal_size);
++
++  GST_WRITE_UINT32_BE (buf, nal_size);
++  res = gst_h264_parser_identify_nalu_avc (parser, buf, 0, buf_size, 4, &nalu);
++
++  assert_equals_int (res, GST_H264_PARSER_OK);
++  assert_equals_int (nalu.type, GST_H264_NAL_SLICE_DPA);
++  assert_equals_int (nalu.offset, 4);
++  assert_equals_int (nalu.size, nal_size);
++
++  GST_WRITE_UINT32_BE (buf, G_MAXUINT32);
++  res = gst_h264_parser_identify_nalu_avc (parser, buf, 0, buf_size, 4, &nalu);
++
++  assert_equals_int (res, GST_H264_PARSER_BROKEN_DATA);
++
++  GST_WRITE_UINT32_BE (buf, G_MAXUINT32 - 2);
++  res = gst_h264_parser_identify_nalu_avc (parser, buf, 0, buf_size, 4, &nalu);
++
++  assert_equals_int (res, GST_H264_PARSER_BROKEN_DATA);
++
++  GST_WRITE_UINT32_BE (buf, G_MAXUINT32 - 3);
++  res = gst_h264_parser_identify_nalu_avc (parser, buf, 0, buf_size, 4, &nalu);
++
++  assert_equals_int (res, GST_H264_PARSER_BROKEN_DATA);
++
++  GST_WRITE_UINT32_BE (buf, G_MAXUINT32 - 4);
++  res = gst_h264_parser_identify_nalu_avc (parser, buf, 0, buf_size, 4, &nalu);
++
++  assert_equals_int (res, GST_H264_PARSER_NO_NAL_END);
++
++  GST_WRITE_UINT32_BE (buf, G_MAXUINT32 - 6);
++  res = gst_h264_parser_identify_nalu_avc (parser, buf, 0, buf_size, 4, &nalu);
++
++  assert_equals_int (res, GST_H264_PARSER_NO_NAL_END);
++
++  g_free (buf);
++  gst_h264_nal_parser_free (parser);
++}
++
++GST_END_TEST;
++
+ static guint8 nalu_sps_with_vui[] = {
+   0x00, 0x00, 0x00, 0x01, 0x67, 0x64, 0x00, 0x28,
+   0xac, 0xd9, 0x40, 0x78, 0x04, 0x4f, 0xde, 0x03,
+@@ -666,6 +725,7 @@ h264parser_suite (void)
+   tcase_add_test (tc_chain, test_h264_parse_slice_dpa);
+   tcase_add_test (tc_chain, test_h264_parse_slice_eoseq_slice);
+   tcase_add_test (tc_chain, test_h264_parse_slice_5bytes);
++  tcase_add_test (tc_chain, test_h264_parse_identify_nalu_avc);
+   tcase_add_test (tc_chain, test_h264_parse_invalid_sei);
+   tcase_add_test (tc_chain, test_h264_create_sei);
+ 
+diff --git a/tests/check/libs/h265parser.c b/tests/check/libs/h265parser.c
+index 0a0e4db97..5b6a215ec 100644
+--- a/tests/check/libs/h265parser.c
++++ b/tests/check/libs/h265parser.c
+@@ -255,6 +255,65 @@ GST_START_TEST (test_h265_parse_slice_6bytes)
+ 
+ GST_END_TEST;
+ 
++GST_START_TEST (test_h265_parse_identify_nalu_hevc)
++{
++  GstH265ParserResult res;
++  GstH265NalUnit nalu;
++  GstH265Parser *parser = gst_h265_parser_new ();
++  /* Skip 4 bytes for the start code */
++  const gsize nal_size = sizeof (slice_eos_slice_eob) - 4;
++  const gsize buf_size = 4 + nal_size;
++  guint8 *buf = g_new (guint8, buf_size);
++
++  memcpy (buf + 4, slice_eos_slice_eob + 4, nal_size);
++
++  GST_WRITE_UINT16_BE (buf + 2, nal_size);
++  res = gst_h265_parser_identify_nalu_hevc (parser, buf, 2, buf_size, 2, &nalu);
++
++  assert_equals_int (res, GST_H265_PARSER_OK);
++  assert_equals_int (nalu.type, GST_H265_NAL_SLICE_IDR_W_RADL);
++  assert_equals_int (nalu.offset, 4);
++  assert_equals_int (nalu.size, nal_size);
++
++  GST_WRITE_UINT32_BE (buf, nal_size);
++  res = gst_h265_parser_identify_nalu_hevc (parser, buf, 0, buf_size, 4, &nalu);
++
++  assert_equals_int (res, GST_H265_PARSER_OK);
++  assert_equals_int (nalu.type, GST_H265_NAL_SLICE_IDR_W_RADL);
++  assert_equals_int (nalu.offset, 4);
++  assert_equals_int (nalu.size, nal_size);
++
++  GST_WRITE_UINT32_BE (buf, G_MAXUINT32);
++  res = gst_h265_parser_identify_nalu_hevc (parser, buf, 0, buf_size, 4, &nalu);
++
++  assert_equals_int (res, GST_H265_PARSER_BROKEN_DATA);
++
++  GST_WRITE_UINT32_BE (buf, G_MAXUINT32 - 2);
++  res = gst_h265_parser_identify_nalu_hevc (parser, buf, 0, buf_size, 4, &nalu);
++
++  assert_equals_int (res, GST_H265_PARSER_BROKEN_DATA);
++
++  GST_WRITE_UINT32_BE (buf, G_MAXUINT32 - 3);
++  res = gst_h265_parser_identify_nalu_hevc (parser, buf, 0, buf_size, 4, &nalu);
++
++  assert_equals_int (res, GST_H265_PARSER_BROKEN_DATA);
++
++  GST_WRITE_UINT32_BE (buf, G_MAXUINT32 - 4);
++  res = gst_h265_parser_identify_nalu_hevc (parser, buf, 0, buf_size, 4, &nalu);
++
++  assert_equals_int (res, GST_H265_PARSER_NO_NAL_END);
++
++  GST_WRITE_UINT32_BE (buf, G_MAXUINT32 - 6);
++  res = gst_h265_parser_identify_nalu_hevc (parser, buf, 0, buf_size, 4, &nalu);
++
++  assert_equals_int (res, GST_H265_PARSER_NO_NAL_END);
++
++  g_free (buf);
++  gst_h265_parser_free (parser);
++}
++
++GST_END_TEST;
++
+ GST_START_TEST (test_h265_base_profiles)
+ {
+   GstH265ProfileTierLevel ptl;
+@@ -1101,6 +1160,7 @@ h265parser_suite (void)
+   tcase_add_test (tc_chain, test_h265_parse_slice_eos_slice_eob);
+   tcase_add_test (tc_chain, test_h265_parse_pic_timing);
+   tcase_add_test (tc_chain, test_h265_parse_slice_6bytes);
++  tcase_add_test (tc_chain, test_h265_parse_identify_nalu_hevc);
+   tcase_add_test (tc_chain, test_h265_base_profiles);
+   tcase_add_test (tc_chain, test_h265_base_profiles_compat);
+   tcase_add_test (tc_chain, test_h265_format_range_profiles_exact_match);
+-- 
+2.31.1
+
-- 
2.31.1