[FFmpeg-cvslog] qt-faststart: add validation on ftyp atom size

[erankor]

ffmpeg | branch: master | erankor <eran.kornblau at kaltura.com> | Wed Jun 13 11:48:20 2018 +0300| [ee09ffbfd2f744e796d6289523f396d830c025a3] | committer: Michael Niedermayer

qt-faststart: add validation on ftyp atom size

avoid trying to allocate an unreasonably sized buffer on corrupt files

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=ee09ffbfd2f744e796d6289523f396d830c025a3
---

 tools/qt-faststart.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/qt-faststart.c b/tools/qt-faststart.c
index d0ae7245f3..9446c11f80 100644
--- a/tools/qt-faststart.c
+++ b/tools/qt-faststart.c
@@ -84,6 +84,7 @@
 
 #define ATOM_PREAMBLE_SIZE    8
 #define COPY_BUFFER_SIZE   33554432
+#define MAX_FTYP_ATOM_SIZE 1048576
 
 int main(int argc, char *argv[])
 {
@@ -133,6 +134,11 @@ int main(int argc, char *argv[])
 
         /* keep ftyp atom */
         if (atom_type == FTYP_ATOM) {
+            if (atom_size > MAX_FTYP_ATOM_SIZE) {
+                printf("ftyp atom size %"PRIu64" too big\n",
+                       atom_size);
+                goto error_out;
+            }
             ftyp_atom_size = atom_size;
             free(ftyp_atom);
             ftyp_atom = malloc(ftyp_atom_size);