ffmdec: reject zero-sized chunks
authorAndreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Wed, 2 Dec 2015 21:47:12 +0000 (22:47 +0100)
committerAndreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Fri, 4 Dec 2015 14:20:04 +0000 (15:20 +0100)
If size is zero, avio_get_str fails, leaving the buffer uninitialized.
This causes invalid reads in av_set_options_string.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
libavformat/ffmdec.c

index 9ad771e..afba905 100644 (file)
@@ -423,7 +423,7 @@ static int ffm2_read_header(AVFormatContext *s)
             }
             break;
         case MKBETAG('S', '2', 'V', 'I'):
-            if (f_stvi++) {
+            if (f_stvi++ || !size) {
                 ret = AVERROR(EINVAL);
                 goto fail;
             }
@@ -438,7 +438,7 @@ static int ffm2_read_header(AVFormatContext *s)
                 goto fail;
             break;
         case MKBETAG('S', '2', 'A', 'U'):
-            if (f_stau++) {
+            if (f_stau++ || !size) {
                 ret = AVERROR(EINVAL);
                 goto fail;
             }