evaluate: reject set in concatenation

Consider the following ruleset.

 define ext_if = { "eth0", "eth1" }
 table ip filter {
    chain c {
        iifname . tcp dport { $ext_if . 22 } accept
    }
 }

Attempting to load this ruleset results in:

BUG: invalid expression type 'set' in setnft: netlink.c:304: __netlink_gen_concat_key: Assertion `0' failed.
Aborted (core dumped)

After this patch:

 # nft -f ruleset.nft
 ruleset.nft:1:17-40: Error: cannot use set in concatenation
 define ext_if = { "eth0", "eth1" }
                 ^^^^^^^^^^^^^^^^^^

Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1715
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/src/evaluate.c b/src/evaluate.c
index 2196e92813d04b885d4c48808d508d8bd924e5c1..894987df7895928356a5555185165b1314b33813 100644 (file)
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -1511,6 +1511,12 @@ static int expr_evaluate_concat(struct eval_ctx *ctx, struct expr **expr)
 
                if (list_member_evaluate(ctx, &i) < 0)
                        return -1;
+
+               if (i->etype == EXPR_SET)
+                       return expr_error(ctx->msgs, i,
+                                         "cannot use %s in concatenation",
+                                         expr_name(i));
+
                flags &= i->flags;
 
                if (!key && i->dtype->type == TYPE_INTEGER) {