[FFmpeg-cvslog] avcodec/hevc_ps: Check delta_pocs in ff_hevc_decode_short_term_rps()

[Michael Niedermayer]

ffmpeg | branch: release/3.1 | Michael Niedermayer <michael at niedermayer.cc> | Mon Aug 21 00:18:48 2017 +0200| [0575adfd4a59a0cef51e3ca081896a348c07c12e] | committer: Michael Niedermayer

avcodec/hevc_ps: Check delta_pocs in ff_hevc_decode_short_term_rps()

Fixes: integer overflow
Fixes: 2893/clusterfuzz-testcase-minimized-5809330567774208

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 2b44dcbc44e99daf9515753e9fd4c2e1ea53a2fa)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=0575adfd4a59a0cef51e3ca081896a348c07c12e
---

 libavcodec/hevc_ps.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/libavcodec/hevc_ps.c b/libavcodec/hevc_ps.c
index 87e807bdd3..b58689ab68 100644
--- a/libavcodec/hevc_ps.c
+++ b/libavcodec/hevc_ps.c
@@ -224,6 +224,12 @@ int ff_hevc_decode_short_term_rps(GetBitContext *gb, AVCodecContext *avctx,
             prev = 0;
             for (i = 0; i < rps->num_negative_pics; i++) {
                 delta_poc = get_ue_golomb_long(gb) + 1;
+                if (delta_poc < 1 || delta_poc > 32768) {
+                    av_log(avctx, AV_LOG_ERROR,
+                        "Invalid value of delta_poc: %d\n",
+                        delta_poc);
+                    return AVERROR_INVALIDDATA;
+                }
                 prev -= delta_poc;
                 rps->delta_poc[i] = prev;
                 rps->used[i]      = get_bits1(gb);
@@ -231,6 +237,12 @@ int ff_hevc_decode_short_term_rps(GetBitContext *gb, AVCodecContext *avctx,
             prev = 0;
             for (i = 0; i < nb_positive_pics; i++) {
                 delta_poc = get_ue_golomb_long(gb) + 1;
+                if (delta_poc < 1 || delta_poc > 32768) {
+                    av_log(avctx, AV_LOG_ERROR,
+                        "Invalid value of delta_poc: %d\n",
+                        delta_poc);
+                    return AVERROR_INVALIDDATA;
+                }
                 prev += delta_poc;
                 rps->delta_poc[rps->num_negative_pics + i] = prev;
                 rps->used[rps->num_negative_pics + i]      = get_bits1(gb);