On 8/6/2020 12:15 PM, Xu, Guangxin wrote: > Hi James, > Thanks for the review. > How about we add a new function in av1dec.c like this: > > static inline int read_obu_header_with_size_flag(const uint8_t *buf, int > buf_size, > int64_t *obu_size, int *type); > then we can remove first two patches and check has_size_flag in the function.
You mean duplicating the implementation of parse_obu_header() in av1dec.c? > > I guess "out of array reads" will not happen in low overhead obu, since it > always prepare enough data the obu. > > >> -----Original Message----- >> From: ffmpeg-devel <ffmpeg-devel-boun...@ffmpeg.org> On Behalf Of James >> Almer >> Sent: Thursday, August 6, 2020 10:03 PM >> To: ffmpeg-devel@ffmpeg.org >> Subject: Re: [FFmpeg-devel] [PATCH 2/5] av1_parser: do not check buf_size if >> we have size in obu header >> >> On 8/6/2020 5:04 AM, Xu Guangxin wrote: >>> for low overhead obu, we can't forsee the obu size. we can only get it >>> when we parsed the obu header. >>> --- >>> libavcodec/av1_parse.h | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/libavcodec/av1_parse.h b/libavcodec/av1_parse.h index >>> a3b39f039c..823bdedd5e 100644 >>> --- a/libavcodec/av1_parse.h >>> +++ b/libavcodec/av1_parse.h >>> @@ -135,7 +135,7 @@ static inline int parse_obu_header(const uint8_t >>> *buf, int buf_size, >>> >>> size = *obu_size + *start_pos; >>> >>> - if (size > buf_size) >>> + if (!*has_size_flag && size > buf_size) >> >> This check was added in c27c7b49dc to fix out of array reads, so this change >> will >> surely reintroduce the issue. >> >> Also, when has_size_flag is 0, size will never be bigger than buf_size >> because it >> will be derived from it, meaning this change is the same as removing the >> check >> altogether. >> >>> return AVERROR_INVALIDDATA; >>> >>> return size; >>> >> >> _______________________________________________ >> 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". > _______________________________________________ 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".
