[FFmpeg-devel] [PATCH] avformat/dhav: Don't truncate return value of avio_skip()
Andreas Rheinhardt
andreas.rheinhardt at outlook.com
Mon May 9 22:18:32 EEST 2022
Andreas Rheinhardt:
> Fixes demuxing files bigger than INT_MAX.
>
> Reported-by: jenster
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> ---
> This has just been reported by jenster on IRC:
>
> <jenster> I found a bug in libavformat/dhav.c where it fails to demux files > INT_MAX. It's basically assigning the result of avio_skip (which returns an int64_t file offset) to an int in two places which it then checks if it's less than 0 and when the file is bigger than INT_MAX it overflows and becomes negative and errors out (this seems like something
> <jenster> that static analysis should find). It's a two line fix (basically just change two ints to int64_t) https://pastebin.com/iUGe9cza (licensed CC0). Would anyone be able to submit this change or fix it their own way? I don't care about credit and I really don't want to bother with the whole patch submission process for this trivial change.
>
> libavformat/dhav.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/libavformat/dhav.c b/libavformat/dhav.c
> index 60aab8cabd..9d26efe8fc 100644
> --- a/libavformat/dhav.c
> +++ b/libavformat/dhav.c
> @@ -78,10 +78,11 @@ static const uint32_t sample_rates[] = {
> static int parse_ext(AVFormatContext *s, int length)
> {
> DHAVContext *dhav = s->priv_data;
> - int index, ret = 0;
> + int64_t ret = 0;
>
> while (length > 0) {
> int type = avio_r8(s->pb);
> + int index;
>
> switch (type) {
> case 0x80:
> @@ -168,8 +169,7 @@ static int read_chunk(AVFormatContext *s)
> {
> DHAVContext *dhav = s->priv_data;
> int frame_length, ext_length;
> - int64_t start, end;
> - int ret;
> + int64_t start, end, ret;
>
> if (avio_feof(s->pb))
> return AVERROR_EOF;
Will apply later today unless there are objections.
- Andreas
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