From 2610acb49a140901dacbd36c598a5514cf9ade0d Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 31 Oct 2020 23:46:33 +0100 Subject: [PATCH] avformat/concatdec: use av_strstart() Fixes: out array read Fixes: 26610/clusterfuzz-testcase-minimized-ffmpeg_dem_CONCAT_fuzzer-5631838049271808 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Reviewed-by: Andreas Rheinhardt Reviewed-by: Nicolas George Signed-off-by: Michael Niedermayer --- libavformat/concatdec.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/libavformat/concatdec.c b/libavformat/concatdec.c index 4b56b61404..6d5b9914f9 100644 --- a/libavformat/concatdec.c +++ b/libavformat/concatdec.c @@ -113,7 +113,8 @@ static int add_file(AVFormatContext *avf, char *filename, ConcatFile **rfile, ConcatFile *file; char *url = NULL; const char *proto; - size_t url_len, proto_len; + const char *ptr; + size_t url_len; int ret; if (cat->safe > 0 && !safe_filename(filename)) { @@ -122,9 +123,8 @@ static int add_file(AVFormatContext *avf, char *filename, ConcatFile **rfile, } proto = avio_find_protocol_name(filename); - proto_len = proto ? strlen(proto) : 0; - if (proto && !memcmp(filename, proto, proto_len) && - (filename[proto_len] == ':' || filename[proto_len] == ',')) { + if (proto && av_strstart(filename, proto, &ptr) && + (*ptr == ':' || *ptr == ',')) { url = filename; filename = NULL; } else {