Guo, Yejun: > > >> -----Original Message----- >> From: ffmpeg-devel <ffmpeg-devel-boun...@ffmpeg.org> On Behalf Of >> Andreas Rheinhardt >> Sent: 2021年2月21日 9:41 >> To: ffmpeg-devel@ffmpeg.org >> Cc: Andreas Rheinhardt <andreas.rheinha...@gmail.com> >> Subject: [FFmpeg-devel] [PATCH 1/2] avcodec/movtextenc: Check for too many >> styles >> >> The counter for the number of styles is written on two bytes, ergo anything > >> UINT16_MAX is invalid. This also fixes a compiler warning because of a >> tautologically true check on 64bit systems. >> >> Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@gmail.com> >> --- >> A better solution would be to error out as soon as the byte length of a >> subtitle >> exceeds UINT16_MAX; yet for this one would have to modify all of ass_split to >> allow the callbacks to return errors. >> >> libavcodec/movtextenc.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/libavcodec/movtextenc.c b/libavcodec/movtextenc.c index >> 1bef21e0b9..cf30adbd0a 100644 >> --- a/libavcodec/movtextenc.c >> +++ b/libavcodec/movtextenc.c >> @@ -355,7 +355,7 @@ static int mov_text_style_start(MovTextContext *s) >> StyleBox *tmp; >> >> // last style != defaults, end the style entry and start a new one >> - if (s->count + 1 > SIZE_MAX / sizeof(*s->style_attributes) || >> + if (s->count + 1 > FFMIN(SIZE_MAX / >> + sizeof(*s->style_attributes), UINT16_MAX) || > > hi, logically, I think the result of FFMIN(SIZE_MAX / > sizeof(*s->style_attributes), UINT16_MAX) is always UINT16_MAX, we may just > use 's->count + 1 > UINT16_MAX'. >
And why? > >> !(tmp = av_fast_realloc(s->style_attributes, >> >> &s->style_attributes_bytes_allocated, >> (s->count + 1) * >> sizeof(*s->style_attributes)))) { >> -- >> 2.27.0 >> >> _______________________________________________ >> 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".