[FFmpeg-cvslog] avcodec/hevc_ps: Fix integer overflow with beta/tc offsets

[Michael Niedermayer]

ffmpeg | branch: release/3.2 | Michael Niedermayer <michael at niedermayer.cc> | Fri Jun 30 16:23:32 2017 +0200| [2b85709bee1678a3a1dfd3e6b03e065eb734a803] | committer: Michael Niedermayer

avcodec/hevc_ps: Fix integer overflow with beta/tc offsets

Fixes: runtime error: signed integer overflow: 2113929216 * 2 cannot be represented in type 'int'
Fixes: 2422/clusterfuzz-testcase-minimized-5242114713583616

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit de54a37c1dfa2817b5838720fac44e82312ccbfd)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=2b85709bee1678a3a1dfd3e6b03e065eb734a803
---

 libavcodec/hevc_ps.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/libavcodec/hevc_ps.c b/libavcodec/hevc_ps.c
index ba5ab2385c..fec81871ab 100644
--- a/libavcodec/hevc_ps.c
+++ b/libavcodec/hevc_ps.c
@@ -1608,20 +1608,22 @@ int ff_hevc_decode_nal_pps(GetBitContext *gb, AVCodecContext *avctx,
         pps->deblocking_filter_override_enabled_flag = get_bits1(gb);
         pps->disable_dbf                             = get_bits1(gb);
         if (!pps->disable_dbf) {
-            pps->beta_offset = get_se_golomb(gb) * 2;
-            pps->tc_offset = get_se_golomb(gb) * 2;
-            if (pps->beta_offset/2 < -6 || pps->beta_offset/2 > 6) {
+            int beta_offset_div2 = get_se_golomb(gb);
+            int tc_offset_div2   = get_se_golomb(gb) ;
+            if (beta_offset_div2 < -6 || beta_offset_div2 > 6) {
                 av_log(avctx, AV_LOG_ERROR, "pps_beta_offset_div2 out of range: %d\n",
-                       pps->beta_offset/2);
+                       beta_offset_div2);
                 ret = AVERROR_INVALIDDATA;
                 goto err;
             }
-            if (pps->tc_offset/2 < -6 || pps->tc_offset/2 > 6) {
+            if (tc_offset_div2 < -6 || tc_offset_div2 > 6) {
                 av_log(avctx, AV_LOG_ERROR, "pps_tc_offset_div2 out of range: %d\n",
-                       pps->tc_offset/2);
+                       tc_offset_div2);
                 ret = AVERROR_INVALIDDATA;
                 goto err;
             }
+            pps->beta_offset = 2 * beta_offset_div2;
+            pps->tc_offset   = 2 *   tc_offset_div2;
         }
     }