On 9/13/22, Andreas Rheinhardt <andreas.rheinha...@outlook.com> wrote: > If a key already exists in an AVDictionary and the AV_DICT_APPEND flag > is set, the old entry is at first discarded from the dictionary, but > a pointer to the value is kept. Lateron enough memory to store the > appended string is allocated; should this allocation fail, the old string > is not freed and hence leaks. This commit changes this by moving > creating the combined value to an earlier point in the function, > which also ensures that the AVDictionaty is unchanged in case of errors. > > Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@outlook.com> > --- > This is an improved version of > https://patchwork.ffmpeg.org/project/ffmpeg/patch/20191111011259.27313-1-andreas.rheinha...@gmail.com/ > > libavutil/dict.c | 28 ++++++++++++---------------- > 1 file changed, 12 insertions(+), 16 deletions(-) > > diff --git a/libavutil/dict.c b/libavutil/dict.c > index a4f638a1fc..c01165634e 100644 > --- a/libavutil/dict.c > +++ b/libavutil/dict.c > @@ -73,7 +73,7 @@ int av_dict_set(AVDictionary **pm, const char *key, const > char *value, > { > AVDictionary *m = *pm; > AVDictionaryEntry *tag = NULL; > - char *oldval = NULL, *copy_key = NULL, *copy_value = NULL; > + char *copy_key = NULL, *copy_value = NULL; > > if (!(flags & AV_DICT_MULTIKEY)) { > tag = av_dict_get(m, key, NULL, flags); > @@ -97,10 +97,17 @@ int av_dict_set(AVDictionary **pm, const char *key, > const char *value, > av_free(copy_value); > return 0; > } > - if (flags & AV_DICT_APPEND) > - oldval = tag->value; > - else > - av_free(tag->value); > + if (copy_value && flags & AV_DICT_APPEND) { > + size_t len = strlen(tag->value) + strlen(copy_value) + 1; > + char *newval = av_mallocz(len); > + if (!newval) > + goto err_out; > + av_strlcat(newval, tag->value, len); > + av_strlcat(newval, copy_value, len); > + av_freep(©_value); > + copy_value = newval; > + } > + av_free(tag->value); > av_free(tag->key); > *tag = m->elems[--m->count]; > } else if (copy_value) { > @@ -113,17 +120,6 @@ int av_dict_set(AVDictionary **pm, const char *key, > const char *value, > if (copy_value) { > m->elems[m->count].key = copy_key; > m->elems[m->count].value = copy_value; > - if (oldval && flags & AV_DICT_APPEND) { > - size_t len = strlen(oldval) + strlen(copy_value) + 1; > - char *newval = av_mallocz(len); > - if (!newval) > - goto err_out; > - av_strlcat(newval, oldval, len); > - av_freep(&oldval); > - av_strlcat(newval, copy_value, len); > - m->elems[m->count].value = newval; > - av_freep(©_value); > - } > m->count++; > } else { > av_freep(©_key); > -- > 2.34.1 >
LGTM > _______________________________________________ > 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". > _______________________________________________ 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".
