[FFmpeg-devel] [PATCH 1/2] avformat/mov: sanity check STSD entries

Michael Niedermayer michael at niedermayer.cc
Sun Feb 7 22:50:02 EET 2021


The choosen value is arbitrary. I am not sure if this is a good idea
but i dont immedeately see an alternative better way, it seems either
an arbitrary limit or OOM

Fixes: OOM
Fixes: 27492/clusterfuzz-testcase-minimized-ffmpeg_dem_MOV_fuzzer-6194970578649088

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavformat/mov.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/mov.c b/libavformat/mov.c
index d9a6a54083..0c44032071 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -2605,7 +2605,7 @@ static int mov_read_stsd(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     entries = avio_rb32(pb);
 
     /* Each entry contains a size (4 bytes) and format (4 bytes). */
-    if (entries <= 0 || entries > atom.size / 8) {
+    if (entries <= 0 || entries > atom.size / 8 || entries > 1024) {
         av_log(c->fc, AV_LOG_ERROR, "invalid STSD entries %d\n", entries);
         return AVERROR_INVALIDDATA;
     }
-- 
2.17.1



More information about the ffmpeg-devel mailing list