netfilter: nfnetlink_cthelper: unbreak userspace helper support
authorPablo Neira Ayuso <pablo@netfilter.org>
Sun, 24 May 2020 19:04:42 +0000 (21:04 +0200)
committerPablo Neira Ayuso <pablo@netfilter.org>
Mon, 25 May 2020 18:39:14 +0000 (20:39 +0200)
Restore helper data size initialization and fix memcopy of the helper
data size.

Fixes: 157ffffeb5dc ("netfilter: nfnetlink_cthelper: reject too large userspace allocation requests")
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
net/netfilter/nfnetlink_cthelper.c

index a5f294a..5b0d0a7 100644 (file)
@@ -103,7 +103,7 @@ nfnl_cthelper_from_nlattr(struct nlattr *attr, struct nf_conn *ct)
        if (help->helper->data_len == 0)
                return -EINVAL;
 
-       nla_memcpy(help->data, nla_data(attr), sizeof(help->data));
+       nla_memcpy(help->data, attr, sizeof(help->data));
        return 0;
 }
 
@@ -240,6 +240,7 @@ nfnl_cthelper_create(const struct nlattr * const tb[],
                ret = -ENOMEM;
                goto err2;
        }
+       helper->data_len = size;
 
        helper->flags |= NF_CT_HELPER_F_USERSPACE;
        memcpy(&helper->tuple, tuple, sizeof(struct nf_conntrack_tuple));