From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netfilter-devel@vger.kernel.org
Cc: davem@davemloft.net, netdev@vger.kernel.org
Subject: [PATCH 4/6] netfilter: nft_compat: explicitly reject ERROR and standard target
Date: Mon, 9 Jul 2018 19:19:02 +0200 [thread overview]
Message-ID: <20180709171904.2460-5-pablo@netfilter.org> (raw)
In-Reply-To: <20180709171904.2460-1-pablo@netfilter.org>
From: Florian Westphal <fw@strlen.de>
iptables-nft never requests these, but make this explicitly illegal.
If it were quested, kernel could oops as ->eval is NULL, furthermore,
the builtin targets have no owning module so its possible to rmmod
eb/ip/ip6_tables module even if they would be loaded.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
net/netfilter/nft_compat.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/net/netfilter/nft_compat.c b/net/netfilter/nft_compat.c
index 8d1ff654e5af..32535eea51b2 100644
--- a/net/netfilter/nft_compat.c
+++ b/net/netfilter/nft_compat.c
@@ -832,10 +832,18 @@ nft_target_select_ops(const struct nft_ctx *ctx,
rev = ntohl(nla_get_be32(tb[NFTA_TARGET_REV]));
family = ctx->family;
+ if (strcmp(tg_name, XT_ERROR_TARGET) == 0 ||
+ strcmp(tg_name, XT_STANDARD_TARGET) == 0 ||
+ strcmp(tg_name, "standard") == 0)
+ return ERR_PTR(-EINVAL);
+
/* Re-use the existing target if it's already loaded. */
list_for_each_entry(nft_target, &nft_target_list, head) {
struct xt_target *target = nft_target->ops.data;
+ if (!target->target)
+ continue;
+
if (nft_target_cmp(target, tg_name, rev, family))
return &nft_target->ops;
}
@@ -844,6 +852,11 @@ nft_target_select_ops(const struct nft_ctx *ctx,
if (IS_ERR(target))
return ERR_PTR(-ENOENT);
+ if (!target->target) {
+ err = -EINVAL;
+ goto err;
+ }
+
if (target->targetsize > nla_len(tb[NFTA_TARGET_INFO])) {
err = -EINVAL;
goto err;
--
2.11.0
next prev parent reply other threads:[~2018-07-09 17:19 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-09 17:18 [PATCH 0/6] Netfilter fixes for net Pablo Neira Ayuso
2018-07-09 17:18 ` [PATCH 1/6] netfilter: x_tables: set module owner for icmp(6) matches Pablo Neira Ayuso
2018-07-09 17:19 ` [PATCH 2/6] netfilter: nf_tproxy: fix possible non-linear access to transport header Pablo Neira Ayuso
2018-07-09 17:19 ` [PATCH 3/6] netfilter: nf_tables: place all set backends in one single module Pablo Neira Ayuso
2018-07-09 17:19 ` Pablo Neira Ayuso [this message]
2018-07-09 17:19 ` [PATCH 5/6] netfilter: nf_conntrack: Fix possible possible crash on module loading Pablo Neira Ayuso
2018-07-09 17:19 ` [PATCH 6/6] netfilter: ipv6: nf_defrag: drop skb dst before queueing Pablo Neira Ayuso
2018-07-09 21:24 ` [PATCH 0/6] Netfilter fixes for net David Miller
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