wmavoice: fix stack overread.

Message ID 20120322192027.F42375E0B1@aruru.libav.org
State New
Headers show

Commit Message

Janne Grunau March 22, 2012, 7:20 p.m.
Module: libav
Branch: master
Commit: 262196445cf03fda0f7e41c4b968f4f7bf060e6b

Author:    Ronald S. Bultje <rsbultje@gmail.com>
Committer: Ronald S. Bultje <rsbultje@gmail.com>
Date:      Wed Mar 21 15:47:11 2012 -0700

wmavoice: fix stack overread.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org

---

 libavcodec/wmavoice.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

Patch

diff --git a/libavcodec/wmavoice.c b/libavcodec/wmavoice.c
index 9553089..a222f09 100644
--- a/libavcodec/wmavoice.c
+++ b/libavcodec/wmavoice.c
@@ -1440,8 +1440,7 @@  static int synth_frame(AVCodecContext *ctx, GetBitContext *gb, int frame_idx,
     int pitch[MAX_BLOCKS], last_block_pitch;
 
     /* Parse frame type ("frame header"), see frame_descs */
-    int bd_idx = s->vbm_tree[get_vlc2(gb, frame_type_vlc.table, 6, 3)],
-        block_nsamples = MAX_FRAMESIZE / frame_descs[bd_idx].n_blocks;
+    int bd_idx = s->vbm_tree[get_vlc2(gb, frame_type_vlc.table, 6, 3)], block_nsamples;
 
     if (bd_idx < 0) {
         av_log(ctx, AV_LOG_ERROR,
@@ -1449,6 +1448,8 @@  static int synth_frame(AVCodecContext *ctx, GetBitContext *gb, int frame_idx,
         return -1;
     }
 
+    block_nsamples = MAX_FRAMESIZE / frame_descs[bd_idx].n_blocks;
+
     /* Pitch calculation for ACB_TYPE_ASYMMETRIC ("pitch-per-frame") */
     if (frame_descs[bd_idx].acb_type == ACB_TYPE_ASYMMETRIC) {
         /* Pitch is provided per frame, which is interpreted as the pitch of