diff mbox

[net] netfilter: nftables: Do not run chains in the wrong network namespace

Message ID 87oakbg0ym.fsf@x220.int.ebiederm.org
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

Eric W. Biederman June 19, 2015, 3:41 p.m. UTC
Currenlty nf_tables chains added in one network namespace are being
run in all network namespace.  The issues are myriad with the simplest
being an unprivileged user can cause any network packets to be dropped.

Address this by simply not running nf_tables chains in the wrong
network namespace.

Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 net/netfilter/nf_tables_core.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Comments

Pablo Neira Ayuso June 19, 2015, 5:21 p.m. UTC | #1
On Fri, Jun 19, 2015 at 10:41:21AM -0500, Eric W. Biederman wrote:
> 
> Currenlty nf_tables chains added in one network namespace are being
> run in all network namespace.  The issues are myriad with the simplest
> being an unprivileged user can cause any network packets to be dropped.
> 
> Address this by simply not running nf_tables chains in the wrong
> network namespace.
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>

@David: Patrick sent a similar patch to address this, if you can get
this into the net tree, I'll make sure this propagates to -stable.
Thanks.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
David Miller June 23, 2015, 1:23 p.m. UTC | #2
From: ebiederm@xmission.com (Eric W. Biederman)
Date: Fri, 19 Jun 2015 10:41:21 -0500

> 
> Currenlty nf_tables chains added in one network namespace are being
> run in all network namespace.  The issues are myriad with the simplest
> being an unprivileged user can cause any network packets to be dropped.
> 
> Address this by simply not running nf_tables chains in the wrong
> network namespace.
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

Applied.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c
index f153b07073af..f77bad46ac68 100644
--- a/net/netfilter/nf_tables_core.c
+++ b/net/netfilter/nf_tables_core.c
@@ -114,7 +114,8 @@  unsigned int
 nft_do_chain(struct nft_pktinfo *pkt, const struct nf_hook_ops *ops)
 {
 	const struct nft_chain *chain = ops->priv, *basechain = chain;
-	const struct net *net = read_pnet(&nft_base_chain(basechain)->pnet);
+	const struct net *chain_net = read_pnet(&nft_base_chain(basechain)->pnet);
+	const struct net *net = dev_net(pkt->in ? pkt->in : pkt->out);
 	const struct nft_rule *rule;
 	const struct nft_expr *expr, *last;
 	struct nft_regs regs;
@@ -124,6 +125,10 @@  nft_do_chain(struct nft_pktinfo *pkt, const struct nf_hook_ops *ops)
 	int rulenum;
 	unsigned int gencursor = nft_genmask_cur(net);
 
+	/* Ignore chains that are not for the current network namespace */
+	if (!net_eq(net, chain_net))
+		return NF_ACCEPT;
+
 do_chain:
 	rulenum = 0;
 	rule = list_entry(&chain->rules, struct nft_rule, list);