ffmpeg | branch: master | Michael Niedermayer <mich...@niedermayer.cc> | Thu Nov 3 11:30:50 2016 +0100| [cee1f4c06986941bd31cc19f4333d436394aa6f9] | committer: Michael Niedermayer
avcodec/ac3dec: Check expacc this is somewhat a magic number, which can be understood from reading section "7.1.2 Exponent Strategy" of the ac3 specification, in short: Three exponents each represented as number 0-4 are grouped together and base-5 encoded, so the maximal correct value is 25*4 + 5*4 + 4 = 124. Reviewed-by: Andreas Cadhalpun <andreas.cadhal...@googlemail.com> Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=cee1f4c06986941bd31cc19f4333d436394aa6f9 --- libavcodec/ac3dec.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/libavcodec/ac3dec.c b/libavcodec/ac3dec.c index a95c204..499971a 100644 --- a/libavcodec/ac3dec.c +++ b/libavcodec/ac3dec.c @@ -426,6 +426,10 @@ static int decode_exponents(AC3DecodeContext *s, group_size = exp_strategy + (exp_strategy == EXP_D45); for (grp = 0, i = 0; grp < ngrps; grp++) { expacc = get_bits(gbc, 7); + if (expacc >= 125) { + av_log(s->avctx, AV_LOG_ERROR, "expacc %d is out-of-range\n", expacc); + return AVERROR_INVALIDDATA; + } dexp[i++] = ungroup_3_in_7_bits_tab[expacc][0]; dexp[i++] = ungroup_3_in_7_bits_tab[expacc][1]; dexp[i++] = ungroup_3_in_7_bits_tab[expacc][2]; _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog
