fix rejection of dns responses with pointers past 512 byte offset

[musl] / src / network / res_mkquery.c

diff --git a/src/network/res_mkquery.c b/src/network/res_mkquery.c
index 33f50cb..614bf78 100644 (file)
--- a/src/network/res_mkquery.c
+++ b/src/network/res_mkquery.c
@@ -13,6 +13,7 @@ int __res_mkquery(int op, const char *dname, int class, int type,
        int n;
 
        if (l && dname[l-1]=='.') l--;
+       if (l && dname[l-1]=='.') return -1;
        n = 17+l+!!l;
        if (l>253 || buflen<n || op>15u || class>255u || type>255u)
                return -1;