alsdec: check block length
authorReinhard Tartler <siretart@tauware.de>
Sun, 8 Dec 2013 18:24:26 +0000 (13:24 -0500)
committerReinhard Tartler <siretart@tauware.de>
Sat, 14 Dec 2013 17:51:40 +0000 (12:51 -0500)
Fix writing over the end

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Addresses: CVE-2013-0845
(cherry picked from commit 2a0fb7286d67c47e44aa76c237ede117b22af616)

Signed-off-by: Reinhard Tartler <siretart@tauware.de>
libavcodec/alsdec.c

index f1d01a2..cb942c2 100644 (file)
@@ -1380,6 +1380,11 @@ static int read_frame_data(ALSDecContext *ctx, unsigned int ra_frame)
 
         for (b = 0; b < ctx->num_blocks; b++) {
             bd.block_length = div_blocks[b];
+            if (bd.block_length <= 0) {
+                av_log(ctx->avctx, AV_LOG_WARNING,
+                       "Invalid block length %d in channel data!\n", bd.block_length);
+                continue;
+            }
 
             for (c = 0; c < avctx->channels; c++) {
                 bd.const_block = ctx->const_block + c;