[FFmpeg-cvslog] avcodec/diracdec: Check slice numbers for overflows in relation to picture dimensions

[Michael Niedermayer]

ffmpeg | branch: release/3.4 | Michael Niedermayer <michael at niedermayer.cc> | Sun Jul 22 21:26:24 2018 +0200| [a594ce26ce3842a1a52558bcfc3f8f57fd5c6f45] | committer: Michael Niedermayer

avcodec/diracdec: Check slice numbers for overflows in relation to picture dimensions

Fixes: signed integer overflow: 88 * 33685506 cannot be represented in type 'int'
Fixes: 9433/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_DIRAC_fuzzer-5725943535501312

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 f457c0ad7f73e31e99761f2ad3738cf3b3c24ca0)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a594ce26ce3842a1a52558bcfc3f8f57fd5c6f45
---

 libavcodec/diracdec.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libavcodec/diracdec.c b/libavcodec/diracdec.c
index 376732c310..2ceb2234c6 100644
--- a/libavcodec/diracdec.c
+++ b/libavcodec/diracdec.c
@@ -1242,7 +1242,10 @@ static int dirac_unpack_idwt_params(DiracContext *s)
     else {
         s->num_x        = get_interleaved_ue_golomb(gb);
         s->num_y        = get_interleaved_ue_golomb(gb);
-        if (s->num_x * s->num_y == 0 || s->num_x * (uint64_t)s->num_y > INT_MAX) {
+        if (s->num_x * s->num_y == 0 || s->num_x * (uint64_t)s->num_y > INT_MAX ||
+            s->num_x * (uint64_t)s->avctx->width  > INT_MAX ||
+            s->num_y * (uint64_t)s->avctx->height > INT_MAX
+        ) {
             av_log(s->avctx,AV_LOG_ERROR,"Invalid numx/y\n");
             s->num_x = s->num_y = 0;
             return AVERROR_INVALIDDATA;