| From 6df0d3e2916c223dbe4262bf1b876dff1cb3f980 Mon Sep 17 00:00:00 2001 |
| From: Michael Niedermayer <michaelni@gmx.at> |
| 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 <michaelni@gmx.at> |
| (cherry picked from commit 0ceca269b66ec12a23bf0907bd2c220513cdbf16) |
| |
| Signed-off-by: Michael Niedermayer <michaelni@gmx.at> |
| --- |
| 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; |
| -- |