From 3433f038998589040880c526208191c4b48f39c2 Mon Sep 17 00:00:00 2001 From: Edward Hervey Date: Sat, 26 Nov 2016 10:44:43 +0100 Subject: 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(-) diff --git a/gst-libs/gst/mpegts/gstmpegtssection.c b/gst-libs/gst/mpegts/gstmpegtssection.c index cb9e3c5e7..cc5e21b2a 100644 --- a/gst-libs/gst/mpegts/gstmpegtssection.c +++ b/gst-libs/gst/mpegts/gstmpegtssection.c @@ -1179,13 +1179,20 @@ gst_mpegts_section_new (guint16 pid, guint8 * data, gsize data_size) 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; @@ -1200,6 +1207,13 @@ gst_mpegts_section_new (guint16 pid, guint8 * data, gsize data_size) /* 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 */ @@ -1229,6 +1243,13 @@ 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; + } } /** -- cgit v1.2.1