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authorFlorian Westphal <fw@strlen.de>2019-01-11 14:46:15 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-04-05 22:33:15 +0200
commit2e6bcc327b0b4e64b5cff2a11427bcd046e06a70 (patch)
tree1cfbdf8b444b07058482e24e689fb0e861fb5f9d
parent24296fbc5445d8497382a8a802a5fa6819cbe014 (diff)
netfilter: physdev: relax br_netfilter dependency
[ Upstream commit 8e2f311a68494a6677c1724bdcb10bada21af37c ] Following command: iptables -D FORWARD -m physdev ... causes connectivity loss in some setups. Reason is that iptables userspace will probe kernel for the module revision of the physdev patch, and physdev has an artificial dependency on br_netfilter (xt_physdev use makes no sense unless a br_netfilter module is loaded). This causes the "phydev" module to be loaded, which in turn enables the "call-iptables" infrastructure. bridged packets might then get dropped by the iptables ruleset. The better fix would be to change the "call-iptables" defaults to 0 and enforce explicit setting to 1, but that breaks backwards compatibility. This does the next best thing: add a request_module call to checkentry. This was a stray '-D ... -m physdev' won't activate br_netfilter anymore. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--include/net/netfilter/br_netfilter.h1
-rw-r--r--net/bridge/br_netfilter_hooks.c5
-rw-r--r--net/netfilter/xt_physdev.c9
3 files changed, 7 insertions, 8 deletions
diff --git a/include/net/netfilter/br_netfilter.h b/include/net/netfilter/br_netfilter.h
index 74af19c3a8f7..a4ba601b5d04 100644
--- a/include/net/netfilter/br_netfilter.h
+++ b/include/net/netfilter/br_netfilter.h
@@ -49,7 +49,6 @@ static inline struct rtable *bridge_parent_rtable(const struct net_device *dev)
}
struct net_device *setup_pre_routing(struct sk_buff *skb);
-void br_netfilter_enable(void);
#if IS_ENABLED(CONFIG_IPV6)
int br_validate_ipv6(struct net *net, struct sk_buff *skb);
diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c
index e07a7e62c705..3b0a03b92080 100644
--- a/net/bridge/br_netfilter_hooks.c
+++ b/net/bridge/br_netfilter_hooks.c
@@ -884,11 +884,6 @@ static const struct nf_br_ops br_ops = {
.br_dev_xmit_hook = br_nf_dev_xmit,
};
-void br_netfilter_enable(void)
-{
-}
-EXPORT_SYMBOL_GPL(br_netfilter_enable);
-
/* For br_nf_post_routing, we need (prio = NF_BR_PRI_LAST), because
* br_dev_queue_push_xmit is called afterwards */
static const struct nf_hook_ops br_nf_ops[] = {
diff --git a/net/netfilter/xt_physdev.c b/net/netfilter/xt_physdev.c
index 9d6d67b953ac..05f00fb20b04 100644
--- a/net/netfilter/xt_physdev.c
+++ b/net/netfilter/xt_physdev.c
@@ -96,8 +96,7 @@ match_outdev:
static int physdev_mt_check(const struct xt_mtchk_param *par)
{
const struct xt_physdev_info *info = par->matchinfo;
-
- br_netfilter_enable();
+ static bool brnf_probed __read_mostly;
if (!(info->bitmask & XT_PHYSDEV_OP_MASK) ||
info->bitmask & ~XT_PHYSDEV_OP_MASK)
@@ -111,6 +110,12 @@ static int physdev_mt_check(const struct xt_mtchk_param *par)
if (par->hook_mask & (1 << NF_INET_LOCAL_OUT))
return -EINVAL;
}
+
+ if (!brnf_probed) {
+ brnf_probed = true;
+ request_module("br_netfilter");
+ }
+
return 0;
}