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From d58f668ece8795bddb3316832e1848c7b7cf38ac Mon Sep 17 00:00:00 2001
From: Edward Hervey <edward@centricular.com>
Date: Sat, 26 Nov 2016 10:44:43 +0100
Subject: [PATCH] mpegtssection: Add more section size checks
The smallest section ever needs to be at least 3 bytes (i.e. just the short
header).
Non-short headers need to be at least 11 bytes long (3 for the minimum header,
5 for the non-short header, and 4 for the CRC).
https://bugzilla.gnome.org/show_bug.cgi?id=775048
---
gst-libs/gst/mpegts/gstmpegtssection.c | 23 ++++++++++++++++++++++-
1 file changed, 22 insertions(+), 1 deletion(-)
Index: gst-plugins-bad1.0-1.4.4/gst-libs/gst/mpegts/gstmpegtssection.c
===================================================================
--- gst-plugins-bad1.0-1.4.4.orig/gst-libs/gst/mpegts/gstmpegtssection.c
+++ gst-plugins-bad1.0-1.4.4/gst-libs/gst/mpegts/gstmpegtssection.c
@@ -1175,13 +1175,20 @@ gst_mpegts_section_new (guint16 pid, gui
GstMpegtsSection *res = NULL;
guint8 tmp;
guint8 table_id;
- guint16 section_length;
+ guint16 section_length = 0;
+
+ /* The smallest section ever is 3 bytes */
+ if (G_UNLIKELY (data_size < 3))
+ goto short_packet;
/* Check for length */
section_length = GST_READ_UINT16_BE (data + 1) & 0x0FFF;
if (G_UNLIKELY (data_size < section_length + 3))
goto short_packet;
+ GST_LOG ("data_size:%" G_GSIZE_FORMAT " section_length:%u",
+ data_size, section_length);
+
/* Table id is in first byte */
table_id = *data;
@@ -1196,6 +1203,13 @@ gst_mpegts_section_new (guint16 pid, gui
/* section_length (already parsed) : 12 bit */
res->section_length = section_length + 3;
if (!res->short_section) {
+ /* A long packet needs to be at least 11 bytes long
+ * _ 3 for the bytes above
+ * _ 5 for the bytes below
+ * _ 4 for the CRC */
+ if (G_UNLIKELY (data_size < 11))
+ goto bad_long_packet;
+
/* CRC is after section_length (-4 for the size of the CRC) */
res->crc = GST_READ_UINT32_BE (res->data + res->section_length - 4);
/* Skip to after section_length */
@@ -1225,6 +1239,13 @@ short_packet:
g_free (data);
return NULL;
}
+bad_long_packet:
+ {
+ GST_WARNING ("PID 0x%04x long section is too short (%" G_GSIZE_FORMAT
+ " bytes, need at least 11)", pid, data_size);
+ gst_mpegts_section_unref (res);
+ return NULL;
+ }
}
/**
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