[FFmpeg-devel] [PATCH 1/2] avcodec/movtextenc: Check for too many styles

[Andreas Rheinhardt]

The counter for the number of styles is written on two bytes, ergo
anything > UINT16_MAX is invalid. This also fixes a compiler warning
because of a tautologically true check on 64bit systems.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
---
A better solution would be to error out as soon as the byte length of a
subtitle exceeds UINT16_MAX; yet for this one would have to modify all
of ass_split to allow the callbacks to return errors.

 libavcodec/movtextenc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/movtextenc.c b/libavcodec/movtextenc.c
index 1bef21e0b9..cf30adbd0a 100644
--- a/libavcodec/movtextenc.c
+++ b/libavcodec/movtextenc.c
@@ -355,7 +355,7 @@ static int mov_text_style_start(MovTextContext *s)
         StyleBox *tmp;
 
         // last style != defaults, end the style entry and start a new one
-        if (s->count + 1 > SIZE_MAX / sizeof(*s->style_attributes) ||
+        if (s->count + 1 > FFMIN(SIZE_MAX / sizeof(*s->style_attributes), UINT16_MAX) ||
             !(tmp = av_fast_realloc(s->style_attributes,
                                     &s->style_attributes_bytes_allocated,
                                     (s->count + 1) * sizeof(*s->style_attributes)))) {
-- 
2.27.0