[FFmpeg-devel] [PATCH] avformat/mov: store sample_sizes as unsigned ints

[James Almer <jamrial@gmail.com>]

As defined in Section 8.7.3.2.1 of ISO 14496-12.
Any unsupported value will be rejected in mov_build_index() without outright
aborting demuxing.

Fixes ticket #11005.

Signed-off-by: James Almer <jamrial@gmail.com>
---
 libavformat/isom.h | 2 +-
 libavformat/mov.c  | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/libavformat/isom.h b/libavformat/isom.h
index 07f09d6eff..c0a5788e08 100644
--- a/libavformat/isom.h
+++ b/libavformat/isom.h
@@ -193,7 +193,7 @@ typedef struct MOVStreamContext {
     unsigned int sample_size; ///< may contain value calculated from stsd or value from stsz atom
     unsigned int stsz_sample_size; ///< always contains sample size from stsz atom
     unsigned int sample_count;
-    int *sample_sizes;
+    unsigned int *sample_sizes;
     int keyframe_absent;
     unsigned int keyframe_count;
     int *keyframes;
diff --git a/libavformat/mov.c b/libavformat/mov.c
index b3fa748f27..54c2d1eebc 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -3308,9 +3308,9 @@ static int mov_read_stsz(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 
     for (i = 0; i < entries; i++) {
         sc->sample_sizes[i] = get_bits_long(&gb, field_size);
-        if (sc->sample_sizes[i] < 0) {
+        if (sc->sample_sizes[i] > INT64_MAX - sc->data_size) {
             av_free(buf);
-            av_log(c->fc, AV_LOG_ERROR, "Invalid sample size %d\n", sc->sample_sizes[i]);
+            av_log(c->fc, AV_LOG_ERROR, "Sample size overflow in STSZ\n");
             return AVERROR_INVALIDDATA;
         }
         sc->data_size += sc->sample_sizes[i];
-- 
2.45.1

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