ffmpeg | branch: master | Andreas Rheinhardt <[email protected]> | Tue Sep 13 20:57:05 2022 +0200| [c15dd31d2a9067b3aa7a575f585f44d62e9d5454] | committer: Andreas Rheinhardt
avutil/dict: Fix memleak when using AV_DICT_APPEND 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 AVDictionary is unchanged in case of errors. Reviewed-by: Paul B Mahol <[email protected]> Signed-off-by: Andreas Rheinhardt <[email protected]> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=c15dd31d2a9067b3aa7a575f585f44d62e9d5454 --- libavutil/dict.c | 28 ++++++++++++---------------- 1 file changed, 12 insertions(+), 16 deletions(-) diff --git a/libavutil/dict.c b/libavutil/dict.c index d127bb90aa..aa64fb990c 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 { if (!m->count) { _______________________________________________ ffmpeg-cvslog mailing list [email protected] https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
