[PATCH nft] evaluate: disregard ct address matching without family

* [PATCH nft] evaluate: disregard ct address matching without family
@ 2020-07-31 18:22 Pablo Neira Ayuso
  0 siblings, 0 replies; only message in thread
From: Pablo Neira Ayuso @ 2020-07-31 18:22 UTC (permalink / raw)
  To: netfilter-devel

The following rule:

 # nft add rule ip x y ct original daddr @servers

breaks with:

 # nft list ruleset
nft: netlink_delinearize.c:124: netlink_parse_concat_expr: Assertion `consumed > 0' failed.
Aborted

Bail out if this syntax is used, instead users should rely on:

 # nft add rule ip x y ct original ip daddr @servers
                                   ~~

which uses NFT_CT_{SRC,DST}_{IP,IP6} in the bytecode generation.

This issue is described in 7f742d0a9071 ("ct: support for
NFT_CT_{SRC,DST}_{IP,IP6}").

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 src/evaluate.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/evaluate.c b/src/evaluate.c
index a99b11437342..b64ed3c0c6a4 100644
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -1907,6 +1907,12 @@ static int expr_evaluate_relational(struct eval_ctx *ctx, struct expr **expr)
 							 right);
 			/* fall through */
 		case EXPR_SET_REF:
+			if (rel->left->etype == EXPR_CT &&
+			    (rel->left->ct.key == NFT_CT_SRC ||
+			     rel->left->ct.key == NFT_CT_DST))
+				return expr_error(ctx->msgs, left,
+						  "specify either ip or ip6 for address matching");
+
 			/* Data for range lookups needs to be in big endian order */
 			if (right->set->flags & NFT_SET_INTERVAL &&
 			    byteorder_conversion(ctx, &rel->left, BYTEORDER_BIG_ENDIAN) < 0)
-- 
2.20.1


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