[FFmpeg-devel] [PATCH v3] fftools/opts: Avoid crash when opts could not be allocated

[Yu Yang]

If 'opts' could not be allocated, exiting the program to avoid crash when release it. 
Before setup_find_stream_info_opts(), checking 'orig_nb_streams' is > 0.
If 'orig_nb_streams' == 0, it doesn't need 'opts' to getting streams info. So directly 
execute avformat_find_stream_info().

Reported-by: TOTE Robot <oslab at tsinghua.edu.cn>
Signed-off-by: Yu Yang <young_chelsea at 163.com>
---
 fftools/cmdutils.c   |  5 ++---
 fftools/ffmpeg_opt.c | 20 ++++++++++----------
 2 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/fftools/cmdutils.c b/fftools/cmdutils.c
index 3c8e5a82cd..823cc8a632 100644
--- a/fftools/cmdutils.c
+++ b/fftools/cmdutils.c
@@ -2181,13 +2181,12 @@ AVDictionary **setup_find_stream_info_opts(AVFormatContext *s,
     int i;
     AVDictionary **opts;
 
-    if (!s->nb_streams)
-        return NULL;
     opts = av_calloc(s->nb_streams, sizeof(*opts));
     if (!opts) {
         av_log(NULL, AV_LOG_ERROR,
                "Could not alloc memory for stream options.\n");
-        return NULL;
+        avformat_close_input(&s);
+        exit_program(1);
     }
     for (i = 0; i < s->nb_streams; i++)
         opts[i] = filter_codec_opts(codec_opts, s->streams[i]->codecpar->codec_id,
diff --git a/fftools/ffmpeg_opt.c b/fftools/ffmpeg_opt.c
index a703798586..453f3a21dc 100644
--- a/fftools/ffmpeg_opt.c
+++ b/fftools/ffmpeg_opt.c
@@ -1191,17 +1191,17 @@ static int open_input_file(OptionsContext *o, const char *filename)
         choose_decoder(o, ic, ic->streams[i]);
 
     if (find_stream_info) {
-        AVDictionary **opts = setup_find_stream_info_opts(ic, o->g->codec_opts);
         int orig_nb_streams = ic->nb_streams;
-
-        /* If not enough info to get the stream parameters, we decode the
-           first frames to get it. (used in mpeg case for example) */
-        ret = avformat_find_stream_info(ic, opts);
-
-        for (i = 0; i < orig_nb_streams; i++)
-            av_dict_free(&opts[i]);
-        av_freep(&opts);
-
+        if (orig_nb_streams > 0) {
+            AVDictionary **opts = setup_find_stream_info_opts(ic, o->g->codec_opts);
+            /* If not enough info to get the stream parameters, we decode the
+            first frames to get it. (used in mpeg case for example) */
+            ret = avformat_find_stream_info(ic, opts);
+            for (i = 0; i < orig_nb_streams; i++)
+                av_dict_free(&opts[i]);
+            av_freep(&opts);
+        } else
+            ret = avformat_find_stream_info(ic, NULL);
         if (ret < 0) {
             av_log(NULL, AV_LOG_FATAL, "%s: could not find codec parameters\n", filename);
             if (ic->nb_streams == 0) {
-- 
2.33.1