[FFmpeg-devel] [PATCH] nutdec: check maxpos in read_sm_data before reading count

[Andreas Cadhalpun]

Otherwise sm_size can be larger than size, which results in a negative
packet size.

Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com>
---
 libavformat/nutdec.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/libavformat/nutdec.c b/libavformat/nutdec.c
index 13fb399..43bd27b 100644
--- a/libavformat/nutdec.c
+++ b/libavformat/nutdec.c
@@ -888,7 +888,7 @@ fail:
 
 static int read_sm_data(AVFormatContext *s, AVIOContext *bc, AVPacket *pkt, int is_meta, int64_t maxpos)
 {
-    int count = ffio_read_varlen(bc);
+    int count;
     int skip_start = 0;
     int skip_end = 0;
     int channels = 0;
@@ -898,6 +898,11 @@ static int read_sm_data(AVFormatContext *s, AVIOContext *bc, AVPacket *pkt, int
     int height = 0;
     int i, ret;
 
+    if (avio_tell(bc) >= maxpos)
+        return AVERROR_INVALIDDATA;
+
+    count = ffio_read_varlen(bc);
+
     for (i=0; i<count; i++) {
         uint8_t name[256], str_value[256], type_str[256];
         int value;
-- 
2.1.4