netfilter: nf_tables: fix potential oops when dumping sets

Commit c9c8e48 (netfilter: nf_tables: dump sets in all existing families) changed nft_ctx_init_from_setattr() to only look up the address family if it is not NFPROTO_UNSPEC. However if it is NFPROTO_UNSPEC and a table attribute is given, nftables_afinfo_lookup() will dereference the NULL afi pointer. Fix by checking for non-NULL afi and also move a check added by that commit to the proper position. Signed-off-by: Patrick McHardy <[email protected]> Signed-off-by: Pablo Neira Ayuso <[email protected]>
djekels-zz · Feb 5, 2014 · ec2c993 · ec2c993
1 parent 53b7028
commit ec2c993
Showing 1 changed file with 5 additions and 3 deletions.
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
@@ -1943,6 +1943,9 @@ static int nft_ctx_init_from_setattr(struct nft_ctx *ctx,
 	}
 
 	if (nla[NFTA_SET_TABLE] != NULL) {
+		if (afi == NULL)
+			return -EAFNOSUPPORT;
+
 		table = nf_tables_table_lookup(afi, nla[NFTA_SET_TABLE]);
 		if (IS_ERR(table))
 			return PTR_ERR(table);
@@ -2428,16 +2431,15 @@ static int nf_tables_delset(struct sock *nlsk, struct sk_buff *skb,
 	struct nft_ctx ctx;
 	int err;
 
+	if (nfmsg->nfgen_family == NFPROTO_UNSPEC)
+		return -EAFNOSUPPORT;
 	if (nla[NFTA_SET_TABLE] == NULL)
 		return -EINVAL;
 
 	err = nft_ctx_init_from_setattr(&ctx, skb, nlh, nla);
 	if (err < 0)
 		return err;
 
-	if (nfmsg->nfgen_family == NFPROTO_UNSPEC)
-		return -EAFNOSUPPORT;
-
 	set = nf_tables_set_lookup(ctx.table, nla[NFTA_SET_NAME]);
 	if (IS_ERR(set))
 		return PTR_ERR(set);