From 6df0d3e2916c223dbe4262bf1b876dff1cb3f980 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Wed, 12 Dec 2012 12:28:45 +0100 Subject: [PATCH] alsdec: check block length Upstream-Status: Backport Commit 6df0d3e2916c223dbe4262bf1b876dff1cb3f980 release/1.0 Fix writing over the end Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind Signed-off-by: Michael Niedermayer (cherry picked from commit 0ceca269b66ec12a23bf0907bd2c220513cdbf16) Signed-off-by: Michael Niedermayer --- libavcodec/alsdec.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/libavcodec/alsdec.c b/libavcodec/alsdec.c index 46dd0b4..1095b01 100644 --- a/gst-libs/ext/libav/libavcodec/alsdec.c +++ b/gst-libs/ext/libav/libavcodec/alsdec.c @@ -552,12 +552,15 @@ static void get_block_sizes(ALSDecContext *ctx, unsigned int *div_blocks, /** Read the block data for a constant block */ -static void read_const_block_data(ALSDecContext *ctx, ALSBlockData *bd) +static int read_const_block_data(ALSDecContext *ctx, ALSBlockData *bd) { ALSSpecificConfig *sconf = &ctx->sconf; AVCodecContext *avctx = ctx->avctx; GetBitContext *gb = &ctx->gb; + if (bd->block_length <= 0) + return -1; + *bd->raw_samples = 0; *bd->const_block = get_bits1(gb); // 1 = constant value, 0 = zero block (silence) bd->js_blocks = get_bits1(gb); @@ -572,6 +575,8 @@ static void read_const_block_data(ALSDecContext *ctx, ALSBlockData *bd) // ensure constant block decoding by reusing this field *bd->const_block = 1; + + return 0; } @@ -971,7 +976,8 @@ static int read_block(ALSDecContext *ctx, ALSBlockData *bd) if (read_var_block_data(ctx, bd)) return -1; } else { - read_const_block_data(ctx, bd); + if (read_const_block_data(ctx, bd) < 0) + return -1; } return 0; --