[FFmpeg-cvslog] avformat/mov: Check count sums in build_open_gop_key_points()

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Thu Jul 28 14:42:43 2022 +0200| [c953baa084607dd1d84c3bfcce3cf6a87c3e6e05] | committer: Michael Niedermayer

avformat/mov: Check count sums in build_open_gop_key_points()

Fixes: ffmpeg.md
Fixes: Out of array access
Fixes: CVE-2022-2566

Found-by: Andy Nguyen <theflow at google.com>
Found-by: 3pvd <3pvd at google.com>
Reviewed-by: Andy Nguyen <theflow at google.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=c953baa084607dd1d84c3bfcce3cf6a87c3e6e05
---

 libavformat/mov.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/libavformat/mov.c b/libavformat/mov.c
index 1d8c5b2904..35e2271b14 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -3967,8 +3967,11 @@ static int build_open_gop_key_points(AVStream *st)
 
     /* Build an unrolled index of the samples */
     sc->sample_offsets_count = 0;
-    for (uint32_t i = 0; i < sc->ctts_count; i++)
+    for (uint32_t i = 0; i < sc->ctts_count; i++) {
+        if (sc->ctts_data[i].count > INT_MAX - sc->sample_offsets_count)
+            return AVERROR(ENOMEM);
         sc->sample_offsets_count += sc->ctts_data[i].count;
+    }
     av_freep(&sc->sample_offsets);
     sc->sample_offsets = av_calloc(sc->sample_offsets_count, sizeof(*sc->sample_offsets));
     if (!sc->sample_offsets)
@@ -3987,8 +3990,11 @@ static int build_open_gop_key_points(AVStream *st)
     /* Build a list of open-GOP key samples */
     sc->open_key_samples_count = 0;
     for (uint32_t i = 0; i < sc->sync_group_count; i++)
-        if (sc->sync_group[i].index == cra_index)
+        if (sc->sync_group[i].index == cra_index) {
+            if (sc->sync_group[i].count > INT_MAX - sc->open_key_samples_count)
+                return AVERROR(ENOMEM);
             sc->open_key_samples_count += sc->sync_group[i].count;
+        }
     av_freep(&sc->open_key_samples);
     sc->open_key_samples = av_calloc(sc->open_key_samples_count, sizeof(*sc->open_key_samples));
     if (!sc->open_key_samples)
@@ -3999,6 +4005,8 @@ static int build_open_gop_key_points(AVStream *st)
         if (sg->index == cra_index)
             for (uint32_t j = 0; j < sg->count; j++)
                 sc->open_key_samples[k++] = sample_id;
+        if (sg->count > INT_MAX - sample_id)
+            return AVERROR_PATCHWELCOME;
         sample_id += sg->count;
     }