Fixed out of bounds write

Credit to OSS-Fuzz

diff --git a/coders/sixel.c b/coders/sixel.c
index c54074ae2fd0fc29d855f74242545c3cb1f5954c..d4a427875c5d16be8b35f29d3658ea09a153bdb1 100644 (file)
--- a/coders/sixel.c
+++ b/coders/sixel.c
@@ -377,7 +377,7 @@ MagickBooleanType sixel_decode(unsigned char              /* in */  *p,
             /* DECGRI Graphics Repeat Introducer ! Pn Ch */
             p = get_params(++p, param, &n);
 
-            if (n > 0) {
+            if ((n > 0) && (param[0] > 1)) {
                 repeat_count = param[0];
             }