[FFmpeg-cvslog] dv: check stype

[Michael Niedermayer]

ffmpeg | branch: release/0.8 | Michael Niedermayer <michaelni at gmx.at> | Tue Jan 24 17:48:23 2012 +0100| [bb737d381f6d6413899a0697f426fb082eac66fc] | committer: Reinhard Tartler

dv: check stype

dv: check stype

Fixes part1 of CVE-2011-3929
Possibly fixes part of CVE-2011-3936

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Reviewed-by: Roman Shaposhnik <roman at shaposhnik.org>
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
Signed-off-by: Alex Converse <alex.converse at gmail.com>
(cherry picked from commit 635bcfccd439480003b74a665b5aa7c872c1ad6b)
Signed-off-by: Reinhard Tartler <siretart at tauware.de>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=bb737d381f6d6413899a0697f426fb082eac66fc
---

 libavformat/dv.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/libavformat/dv.c b/libavformat/dv.c
index 4b41e0a..fe6dac6 100644
--- a/libavformat/dv.c
+++ b/libavformat/dv.c
@@ -202,6 +202,12 @@ static int dv_extract_audio_info(DVDemuxContext* c, uint8_t* frame)
     stype = (as_pack[3] & 0x1f);      /* 0 - 2CH, 2 - 4CH, 3 - 8CH */
     quant =  as_pack[4] & 0x07;       /* 0 - 16bit linear, 1 - 12bit nonlinear */
 
+    if (stype > 3) {
+        av_log(c->fctx, AV_LOG_ERROR, "stype %d is invalid\n", stype);
+        c->ach = 0;
+        return 0;
+    }
+
     /* note: ach counts PAIRS of channels (i.e. stereo channels) */
     ach = ((int[4]){  1,  0,  2,  4})[stype];
     if (ach == 1 && quant && freq == 2)