From 5cd8afee99c83b62e1474f122d947de7e4ad9ff5 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 29 Jan 2012 05:04:25 +0100 Subject: [PATCH] diracdec: Check for negative quants which would cause out of array reads. Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind Signed-off-by: Michael Niedermayer --- libavcodec/diracdec.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/libavcodec/diracdec.c b/libavcodec/diracdec.c index c96b37aa4e..049f7592ca 100644 --- a/libavcodec/diracdec.c +++ b/libavcodec/diracdec.c @@ -491,10 +491,16 @@ static inline void codeblock(DiracContext *s, SubBand *b, } if (s->codeblock_mode && !(s->old_delta_quant && blockcnt_one)) { + int quant = b->quant; if (is_arith) - b->quant += dirac_get_arith_int(c, CTX_DELTA_Q_F, CTX_DELTA_Q_DATA); + quant += dirac_get_arith_int(c, CTX_DELTA_Q_F, CTX_DELTA_Q_DATA); else - b->quant += dirac_get_se_golomb(gb); + quant += dirac_get_se_golomb(gb); + if (quant < 0) { + av_log(s->avctx, AV_LOG_ERROR, "Invalid quant\n"); + return; + } + b->quant = quant; } b->quant = FFMIN(b->quant, MAX_QUANT);