[FFmpeg-devel] [PATCH 26/26] avformat/mov: Fix reel_name size check

Andreas Rheinhardt andreas.rheinhardt at gmail.com
Mon Jun 15 01:36:56 EEST 2020


Only read str_size bytes from offset 30 of extradata if the extradata is
indeed at least 30 + str_size bytes long.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
---
Honestly I don't know the spec describing the actual layout of the
reel_name tag, but looking at this code as well as the one in movenc
makes it clear that the check is wrong.

 libavformat/mov.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/mov.c b/libavformat/mov.c
index a59c804d16..4e68532b69 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -2342,7 +2342,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
                 uint32_t format = AV_RB32(st->codecpar->extradata + 22);
                 if (format == AV_RB32("name") && (int64_t)size >= (int64_t)len + 18) {
                     uint16_t str_size = AV_RB16(st->codecpar->extradata + 26); /* string length */
-                    if (str_size > 0 && size >= (int)str_size + 26) {
+                    if (str_size > 0 && size >= (int)str_size + 30) {
                         char *reel_name = av_malloc(str_size + 1);
                         if (!reel_name)
                             return AVERROR(ENOMEM);
-- 
2.20.1



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