adx: check that the offset is not negative

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind CC:libav-stable@libav.org
11 years ago · 5569146d48
parent a6a2282c25
commit 5569146d48
1 changed files with 1 additions and 1 deletions
--- a/libavcodec/adx.c
+++ b/libavcodec/adx.c
@ -48,7 +48,7 @@ int avpriv_adx_decode_header(AVCodecContext *avctx, const uint8_t *buf,
    offset = AV_RB16(buf + 2) + 4;

    /* if copyright string is within the provided data, validate it */
-    if (bufsize >= offset && memcmp(buf + offset - 6, "(c)CRI", 6))
+    if (bufsize >= offset && offset >= 6 && memcmp(buf + offset - 6, "(c)CRI", 6))
        return AVERROR_INVALIDDATA;

    /* check for encoding=3 block_size=18, sample_size=4 */