alsdec: check opt_order.
authorMichael Niedermayer <michaelni@gmx.at>
Sat, 24 Mar 2012 00:39:13 +0000 (01:39 +0100)
committerJustin Ruggles <justin.ruggles@gmail.com>
Mon, 17 Sep 2012 18:17:26 +0000 (14:17 -0400)
Fixes out of array write in quant_cof.
Also make sure no invalid opt_order stays in the context.

Fixes CVE-2012-2775

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: Justin Ruggles <justin.ruggles@gmail.com>
libavcodec/alsdec.c

index ef12253..defe3c4 100644 (file)
@@ -668,6 +668,11 @@ static int read_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
             int opt_order_length = av_ceil_log2(av_clip((bd->block_length >> 3) - 1,
                                                 2, sconf->max_order + 1));
             *bd->opt_order       = get_bits(gb, opt_order_length);
+            if (*bd->opt_order > sconf->max_order) {
+                *bd->opt_order = sconf->max_order;
+                av_log(avctx, AV_LOG_ERROR, "Predictor order too large!\n");
+                return AVERROR_INVALIDDATA;
+            }
         } else {
             *bd->opt_order = sconf->max_order;
         }