[FFmpeg-cvslog] alsdec: Check k used for rice decoder.

[Michael Niedermayer]

ffmpeg | branch: release/0.10 | Michael Niedermayer <michaelni at gmx.at> | Sat Apr  7 17:25:47 2012 +0200| [592ba67815581a0ba371b57a7e3dd3079760fd9d] | committer: Reinhard Tartler

alsdec: Check k used for rice decoder.

Values that fail this check will cause failure of decode_rice()

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
Signed-off-by: Justin Ruggles <justin.ruggles at gmail.com>
(cherry picked from commit 23aae62c2cb4504a09ceb8cd0cabc1c8b260f521)

Signed-off-by: Reinhard Tartler <siretart at tauware.de>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=592ba67815581a0ba371b57a7e3dd3079760fd9d
---

 libavcodec/alsdec.c |    5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libavcodec/alsdec.c b/libavcodec/alsdec.c
index d5e09c5..8932996 100644
--- a/libavcodec/alsdec.c
+++ b/libavcodec/alsdec.c
@@ -651,6 +651,11 @@ static int read_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
         for (k = 1; k < sub_blocks; k++)
             s[k] = s[k - 1] + decode_rice(gb, 0);
     }
+    for (k = 1; k < sub_blocks; k++)
+        if (s[k] > 32) {
+            av_log(avctx, AV_LOG_ERROR, "k invalid for rice code.\n");
+            return AVERROR_INVALIDDATA;
+        }
 
     if (get_bits1(gb))
         *bd->shift_lsbs = get_bits(gb, 4) + 1;