Opts is assigned by setup_find_stream_info_opts(). Opts may be NULL.
This situation is compatible in avformat_find_stream_info().
Before av_dict_free(), the necessary checks were ignored.
// in fftools/ffmpeg_opt.c:1266
1067 static int open_input_file(OptionsContext *o, const char *filename)
1068 {
...
1191 AVDictionary **opts = setup_find_stream_info_opts(ic,
o->g->codec_opts);
...
1196 ret = avformat_find_stream_info(ic, opts);
1197
1198 for (i = 0; i < orig_nb_streams; i++)
1199 av_dict_free(&opts[i]);
...
1342 }
```
```c
// in libavutil/dict.c:203
203 void av_dict_free(AVDictionary **pm)
204 {
205 AVDictionary *m = *pm;
...
215 }
coredump backtrace info:
==6235==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc
0x000006ba9c2f bp 0x7ffc3d5baa30 sp 0x7ffc3d5ba9a0 T0)
==6235==The signal is caused by a READ memory access.
==6235==Hint: address points to the zero page.
#0 0x6ba9c2f in av_dict_free
/home/r1/ffmpeg/ffmpeg-4.4.1/build/src/libavutil/dict.c:205:23
#1 0x4ce5ac in open_input_file
/home/r1/ffmpeg/ffmpeg-4.4.1/build/src/fftools/ffmpeg_opt.c:1199:13
#2 0x4c9dc0 in open_files
/home/r1/ffmpeg/ffmpeg-4.4.1/build/src/fftools/ffmpeg_opt.c:3338:15
#3 0x4c9295 in ffmpeg_parse_options
/home/r1/ffmpeg/ffmpeg-4.4.1/build/src/fftools/ffmpeg_opt.c:3378:11
#4 0x58f241 in main
/home/r1/ffmpeg/ffmpeg-4.4.1/build/src/fftools/ffmpeg.c:4988:11
#5 0x7fe35197f0b2 in __libc_start_main
/build/glibc-eX1tMB/glibc-2.31/csu/../csu/libc-start.c:308:16
#6 0x42033d in _start (/home/r1/ffmpeg/ffmpeg_4.4.1+0x42033d)
Reported-by: TOTE Robot <os...@tsinghua.edu.cn>
Signed-off-by: Yu Yang <young_chel...@163.com>
---
fftools/ffmpeg_opt.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/fftools/ffmpeg_opt.c b/fftools/ffmpeg_opt.c
index a27263b879..a9fc54d948 100644
--- a/fftools/ffmpeg_opt.c
+++ b/fftools/ffmpeg_opt.c
@@ -1197,10 +1197,11 @@ static int open_input_file(OptionsContext *o, const
char *filename)
/* 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 (opts){
+ for (i = 0; i < orig_nb_streams; i++)
+ av_dict_free(&opts[i]);
+ av_freep(&opts);
+ }
if (ret < 0) {
av_log(NULL, AV_LOG_FATAL, "%s: could not find codec
parameters\n", filename);
--
2.33.1
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
To unsubscribe, visit link above, or email
ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
