Patrick Williams | b48b7b4 | 2016-08-17 15:04:38 -0500 | [diff] [blame^] | 1 | From 6df0d3e2916c223dbe4262bf1b876dff1cb3f980 Mon Sep 17 00:00:00 2001 |
| 2 | From: Michael Niedermayer <michaelni@gmx.at> |
| 3 | Date: Wed, 12 Dec 2012 12:28:45 +0100 |
| 4 | Subject: [PATCH] alsdec: check block length |
| 5 | |
| 6 | Upstream-Status: Backport |
| 7 | |
| 8 | Commit 6df0d3e2916c223dbe4262bf1b876dff1cb3f980 release/1.0 |
| 9 | |
| 10 | Fix writing over the end |
| 11 | |
| 12 | Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind |
| 13 | Signed-off-by: Michael Niedermayer <michaelni@gmx.at> |
| 14 | (cherry picked from commit 0ceca269b66ec12a23bf0907bd2c220513cdbf16) |
| 15 | |
| 16 | Signed-off-by: Michael Niedermayer <michaelni@gmx.at> |
| 17 | --- |
| 18 | libavcodec/alsdec.c | 10 ++++++++-- |
| 19 | 1 file changed, 8 insertions(+), 2 deletions(-) |
| 20 | |
| 21 | diff --git a/libavcodec/alsdec.c b/libavcodec/alsdec.c |
| 22 | index 46dd0b4..1095b01 100644 |
| 23 | --- a/gst-libs/ext/libav/libavcodec/alsdec.c |
| 24 | +++ b/gst-libs/ext/libav/libavcodec/alsdec.c |
| 25 | @@ -552,12 +552,15 @@ static void get_block_sizes(ALSDecContext *ctx, unsigned int *div_blocks, |
| 26 | |
| 27 | /** Read the block data for a constant block |
| 28 | */ |
| 29 | -static void read_const_block_data(ALSDecContext *ctx, ALSBlockData *bd) |
| 30 | +static int read_const_block_data(ALSDecContext *ctx, ALSBlockData *bd) |
| 31 | { |
| 32 | ALSSpecificConfig *sconf = &ctx->sconf; |
| 33 | AVCodecContext *avctx = ctx->avctx; |
| 34 | GetBitContext *gb = &ctx->gb; |
| 35 | |
| 36 | + if (bd->block_length <= 0) |
| 37 | + return -1; |
| 38 | + |
| 39 | *bd->raw_samples = 0; |
| 40 | *bd->const_block = get_bits1(gb); // 1 = constant value, 0 = zero block (silence) |
| 41 | bd->js_blocks = get_bits1(gb); |
| 42 | @@ -572,6 +575,8 @@ static void read_const_block_data(ALSDecContext *ctx, ALSBlockData *bd) |
| 43 | |
| 44 | // ensure constant block decoding by reusing this field |
| 45 | *bd->const_block = 1; |
| 46 | + |
| 47 | + return 0; |
| 48 | } |
| 49 | |
| 50 | |
| 51 | @@ -971,7 +976,8 @@ static int read_block(ALSDecContext *ctx, ALSBlockData *bd) |
| 52 | if (read_var_block_data(ctx, bd)) |
| 53 | return -1; |
| 54 | } else { |
| 55 | - read_const_block_data(ctx, bd); |
| 56 | + if (read_const_block_data(ctx, bd) < 0) |
| 57 | + return -1; |
| 58 | } |
| 59 | |
| 60 | return 0; |
| 61 | -- |