Le decadi 20 vendémiaire, an CCXXIII, Thilo Borgmann a écrit : > Hi, > > trying to fix ticket #4018. > > Metadata in mov is silently truncated to 1023 bytes. > This patch allocated a buffer in case of entries found that exceed 1023 bytes. > Fixes ticket #4018 for me. > > Maybe check str_size against an upper limit? > > -Thilo
> >From 365bec36b3b7f1925cfa2310d979a63ef8e3a7e8 Mon Sep 17 00:00:00 2001
> From: Thilo Borgmann <thilo.borgm...@mail.de>
> Date: Sat, 11 Oct 2014 16:09:07 +0200
> Subject: [PATCH] lavf/mov.c: Allocate buffer in case of long metadata entries.
>
> ---
> libavformat/mov.c | 23 ++++++++++++++++-------
> 1 file changed, 16 insertions(+), 7 deletions(-)
>
> diff --git a/libavformat/mov.c b/libavformat/mov.c
> index 4ff46dd..136b1d5 100644
> --- a/libavformat/mov.c
> +++ b/libavformat/mov.c
> @@ -358,24 +358,33 @@ static int mov_read_udta_string(MOVContext *c,
> AVIOContext *pb, MOVAtom atom)
> if (atom.size < 0)
> return AVERROR_INVALIDDATA;
>
> - str_size = FFMIN3(sizeof(str)-1, str_size, atom.size);
> -
> if (parse)
> parse(c, pb, str_size, key);
> else {
> + char *pstr = str;
If you rename str (maybe str_small) and call pstr str instead, I believe
that makes the patch simpler.
> + if (str_size > sizeof(str)-1) { // allocate buffer for long data
> field
> + pstr = av_malloc(str_size);
> + if (!pstr)
> + return AVERROR(ENOMEM);
> + }
> +
> if (data_type == 3 || (data_type == 0 && (langcode < 0x400 ||
> langcode == 0x7fff))) { // MAC Encoded
> - mov_read_mac_string(c, pb, str_size, str, sizeof(str));
> + mov_read_mac_string(c, pb, str_size, pstr, str_size);
> } else {
> - int ret = avio_read(pb, str, str_size);
> + int ret = avio_read(pb, pstr, str_size);
> if (ret != str_size)
> return ret < 0 ? ret : AVERROR_INVALIDDATA;
> - str[str_size] = 0;
> + pstr[str_size] = 0;
> }
> c->fc->event_flags |= AVFMT_EVENT_FLAG_METADATA_UPDATED;
> - av_dict_set(&c->fc->metadata, key, str, 0);
> + av_dict_set(&c->fc->metadata, key, pstr, 0);
> if (*language && strcmp(language, "und")) {
> snprintf(key2, sizeof(key2), "%s-%s", key, language);
> - av_dict_set(&c->fc->metadata, key2, str, 0);
> + av_dict_set(&c->fc->metadata, key2, pstr, 0);
> + }
> +
> + if (str_size > sizeof(str)-1) { // free buffer for long data field
> + av_freep(&pstr);
I think "if (pstr != str)" would be more robust.
Even more robust, if a bit more verbose:
char *pstr = str, *alloc_str = NULL;
if (...) {
pstr = alloc_str = malloc(...);
}
...
av_freep(alloc_str); // unconditionnal
> }
> }
> av_dlog(c->fc, "lang \"%3s\" ", language);
Regards,
--
Nicolas George
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