From f202a1fdf75d0e7f48a2e8d63c2d390cc4b19c85 Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Tue, 20 Sep 2022 22:08:47 +0200 Subject: avformat/dashdec: Fix crash on invalid input/ENOMEM, fix leak In case a SupplementalProperty node exists in an adaptationset, it is searched for a "schemeIdUri" property via xmlGetProp(). Whatever xmlGetProp() returns is then compared via av_strcasecmp() to a string literal. xmlGetProp() can return NULL, namely in case no "schemeIdUri" exists and (given that this string is allocated) presumably also on allocation failure. No check for NULL is done, so this may crash. Furthermore, the string returned by xmlGetProp() needs to be freed with xmlFree(), but this is not done either. This commit fixes both of these issues; they existed since this code has been added in 10d008f0fd9e713e290f626300d66382ad786c49. This has been found while investigating ticket #9697. The continuous leaks might very well be the reason behind the observed slowdown. Reviewed-by: Steven Liu Signed-off-by: Andreas Rheinhardt (cherry picked from commit 14b3830b33075e92f8e2766c0c53e8b6bc570c6c) --- libavformat/dashdec.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/libavformat/dashdec.c b/libavformat/dashdec.c index 63bf7e96a5..2ca91bea8b 100644 --- a/libavformat/dashdec.c +++ b/libavformat/dashdec.c @@ -956,7 +956,11 @@ static int parse_manifest_representation(AVFormatContext *s, const char *url, xmlFree(val); } if (adaptionset_supplementalproperty_node) { - if (!av_strcasecmp(xmlGetProp(adaptionset_supplementalproperty_node,"schemeIdUri"), "http://dashif.org/guidelines/last-segment-number")) { + char *scheme_id_uri = xmlGetProp(adaptionset_supplementalproperty_node, "schemeIdUri"); + if (scheme_id_uri) { + int is_last_segment_number = !av_strcasecmp(scheme_id_uri, "http://dashif.org/guidelines/last-segment-number"); + xmlFree(scheme_id_uri); + if (is_last_segment_number) { val = xmlGetProp(adaptionset_supplementalproperty_node,"value"); if (!val) { av_log(s, AV_LOG_ERROR, "Missing value attribute in adaptionset_supplementalproperty_node\n"); @@ -965,6 +969,7 @@ static int parse_manifest_representation(AVFormatContext *s, const char *url, xmlFree(val); } } + } } fragment_timeline_node = find_child_node_by_name(representation_segmenttemplate_node, "SegmentTimeline"); -- cgit v1.2.3