jpeg2000: Check component number in get_coc() and get_qcc()

Avoid overreads.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: Nicolas Bertrand <nicoinattendu@gmail.com>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

libavcodec/jpeg2000dec.c

@@ -362,6 +362,13 @@ static int get_coc(Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *c,
 
     compno = bytestream2_get_byteu(&s->g);
 
+    if (compno >= s->ncomponents) {
+        av_log(s->avctx, AV_LOG_ERROR,
+               "Invalid compno %d. There are %d components in the image.\n",
+               compno, s->ncomponents);
+        return AVERROR_INVALIDDATA;
+    }
+
     c      += compno;
     c->csty = bytestream2_get_byteu(&s->g);
     get_cox(s, c);
@@ -440,7 +447,15 @@ static int get_qcc(Jpeg2000DecoderContext *s, int n, Jpeg2000QuantStyle *q,
     if (bytestream2_get_bytes_left(&s->g) < 1)
         return AVERROR_INVALIDDATA;
 
-    compno              = bytestream2_get_byteu(&s->g);
+    compno = bytestream2_get_byteu(&s->g);
+
+    if (compno >= s->ncomponents) {
+        av_log(s->avctx, AV_LOG_ERROR,
+               "Invalid compno %d. There are %d components in the image.\n",
+               compno, s->ncomponents);
+        return AVERROR_INVALIDDATA;
+    }
+
     properties[compno] |= HAD_QCC;
     return get_qcx(s, n - 1, q + compno);
 }