[PATCH AUTOSEL 4.19 077/123] netfilter: add missing error handling code for register functions

Sasha Levin
2018-12-05T09:40:29Z

From: Taehee Yoo <ap420073@gmail.com>

[ Upstream commit 584eab291c67894cb17cc87544b9d086228ea70f ]

register_{netdevice/inetaddr/inet6addr}_notifier may return an error
value, this patch adds the code to handle these error paths.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../net/netfilter/ipv4/nf_nat_masquerade.h | 2 +-
.../net/netfilter/ipv6/nf_nat_masquerade.h | 2 +-
net/ipv4/netfilter/ipt_MASQUERADE.c | 7 ++--
net/ipv4/netfilter/nf_nat_masquerade_ipv4.c | 21 +++++++++---
net/ipv4/netfilter/nft_masq_ipv4.c | 4 ++-
net/ipv6/netfilter/ip6t_MASQUERADE.c | 8 +++--
net/ipv6/netfilter/nf_nat_masquerade_ipv6.c | 32 +++++++++++++------
net/ipv6/netfilter/nft_masq_ipv6.c | 4 ++-
net/netfilter/nft_flow_offload.c | 5 ++-
9 files changed, 63 insertions(+), 22 deletions(-)

diff --git a/include/net/netfilter/ipv4/nf_nat_masquerade.h b/include/net/netfilter/ipv4/nf_nat_masquerade.h
index cd24be4c4a99..13d55206bb9f 100644
--- a/include/net/netfilter/ipv4/nf_nat_masquerade.h
+++ b/include/net/netfilter/ipv4/nf_nat_masquerade.h
@@ -9,7 +9,7 @@ nf_nat_masquerade_ipv4(struct sk_buff *skb, unsigned int hooknum,
const struct nf_nat_range2 *range,
const struct net_device *out);

-void nf_nat_masquerade_ipv4_register_notifier(void);
+int nf_nat_masquerade_ipv4_register_notifier(void);
void nf_nat_masquerade_ipv4_unregister_notifier(void);

#endif /*_NF_NAT_MASQUERADE_IPV4_H_ */
diff --git a/include/net/netfilter/ipv6/nf_nat_masquerade.h b/include/net/netfilter/ipv6/nf_nat_masquerade.h
index 0c3b5ebf0bb8..2917bf95c437 100644
--- a/include/net/netfilter/ipv6/nf_nat_masquerade.h
+++ b/include/net/netfilter/ipv6/nf_nat_masquerade.h
@@ -5,7 +5,7 @@
unsigned int
nf_nat_masquerade_ipv6(struct sk_buff *skb, const struct nf_nat_range2 *range,
const struct net_device *out);
-void nf_nat_masquerade_ipv6_register_notifier(void);
+int nf_nat_masquerade_ipv6_register_notifier(void);
void nf_nat_masquerade_ipv6_unregister_notifier(void);

#endif /* _NF_NAT_MASQUERADE_IPV6_H_ */
diff --git a/net/ipv4/netfilter/ipt_MASQUERADE.c b/net/ipv4/netfilter/ipt_MASQUERADE.c
index ce1512b02cb2..fd3f9e8a74da 100644
--- a/net/ipv4/netfilter/ipt_MASQUERADE.c
+++ b/net/ipv4/netfilter/ipt_MASQUERADE.c
@@ -81,9 +81,12 @@ static int __init masquerade_tg_init(void)
int ret;

ret = xt_register_target(&masquerade_tg_reg);
+ if (ret)
+ return ret;

- if (ret == 0)
- nf_nat_masquerade_ipv4_register_notifier();
+ ret = nf_nat_masquerade_ipv4_register_notifier();
+ if (ret)
+ xt_unregister_target(&masquerade_tg_reg);

return ret;
}
diff --git a/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c b/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c
index ad3aeff152ed..4a7c1f207d6e 100644
--- a/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c
+++ b/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c
@@ -133,16 +133,29 @@ static struct notifier_block masq_inet_notifier = {

static atomic_t masquerade_notifier_refcount = ATOMIC_INIT(0);

-void nf_nat_masquerade_ipv4_register_notifier(void)
+int nf_nat_masquerade_ipv4_register_notifier(void)
{
+ int ret;
+
/* check if the notifier was already set */
if (atomic_inc_return(&masquerade_notifier_refcount) > 1)
- return;
+ return 0;

/* Register for device down reports */
- register_netdevice_notifier(&masq_dev_notifier);
+ ret = register_netdevice_notifier(&masq_dev_notifier);
+ if (ret)
+ goto err_dec;
/* Register IP address change reports */
- register_inetaddr_notifier(&masq_inet_notifier);
+ ret = register_inetaddr_notifier(&masq_inet_notifier);
+ if (ret)
+ goto err_unregister;
+
+ return ret;
+err_unregister:
+ unregister_netdevice_notifier(&masq_dev_notifier);
+err_dec:
+ atomic_dec(&masquerade_notifier_refcount);
+ return ret;
}
EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv4_register_notifier);

diff --git a/net/ipv4/netfilter/nft_masq_ipv4.c b/net/ipv4/netfilter/nft_masq_ipv4.c
index f1193e1e928a..6847de1d1db8 100644
--- a/net/ipv4/netfilter/nft_masq_ipv4.c
+++ b/net/ipv4/netfilter/nft_masq_ipv4.c
@@ -69,7 +69,9 @@ static int __init nft_masq_ipv4_module_init(void)
if (ret < 0)
return ret;

- nf_nat_masquerade_ipv4_register_notifier();
+ ret = nf_nat_masquerade_ipv4_register_notifier();
+ if (ret)
+ nft_unregister_expr(&nft_masq_ipv4_type);

return ret;
}
diff --git a/net/ipv6/netfilter/ip6t_MASQUERADE.c b/net/ipv6/netfilter/ip6t_MASQUERADE.c
index 491f808e356a..29c7f1915a96 100644
--- a/net/ipv6/netfilter/ip6t_MASQUERADE.c
+++ b/net/ipv6/netfilter/ip6t_MASQUERADE.c
@@ -58,8 +58,12 @@ static int __init masquerade_tg6_init(void)
int err;

err = xt_register_target(&masquerade_tg6_reg);
- if (err == 0)
- nf_nat_masquerade_ipv6_register_notifier();
+ if (err)
+ return err;
+
+ err = nf_nat_masquerade_ipv6_register_notifier();
+ if (err)
+ xt_unregister_target(&masquerade_tg6_reg);

return err;
}
diff --git a/net/ipv6/netfilter/nf_nat_masquerade_ipv6.c b/net/ipv6/netfilter/nf_nat_masquerade_ipv6.c
index e6eb7cf9b54f..10012fc687b6 100644
--- a/net/ipv6/netfilter/nf_nat_masquerade_ipv6.c
+++ b/net/ipv6/netfilter/nf_nat_masquerade_ipv6.c
@@ -120,8 +120,8 @@ static void iterate_cleanup_work(struct work_struct *work)
* of ipv6 addresses being deleted), we also need to add an upper
* limit to the number of queued work items.
*/
-static int masq_inet_event(struct notifier_block *this,
- unsigned long event, void *ptr)
+static int masq_inet6_event(struct notifier_block *this,
+ unsigned long event, void *ptr)
{
struct inet6_ifaddr *ifa = ptr;
const struct net_device *dev;
@@ -158,20 +158,34 @@ static int masq_inet_event(struct notifier_block *this,
return NOTIFY_DONE;
}

-static struct notifier_block masq_inet_notifier = {
- .notifier_call = masq_inet_event,
+static struct notifier_block masq_inet6_notifier = {
+ .notifier_call = masq_inet6_event,
};

static atomic_t masquerade_notifier_refcount = ATOMIC_INIT(0);

-void nf_nat_masquerade_ipv6_register_notifier(void)
+int nf_nat_masquerade_ipv6_register_notifier(void)
{
+ int ret;
+
/* check if the notifier is already set */
if (atomic_inc_return(&masquerade_notifier_refcount) > 1)
- return;
+ return 0;

- register_netdevice_notifier(&masq_dev_notifier);
- register_inet6addr_notifier(&masq_inet_notifier);
+ ret = register_netdevice_notifier(&masq_dev_notifier);
+ if (ret)
+ goto err_dec;
+
+ ret = register_inet6addr_notifier(&masq_inet6_notifier);
+ if (ret)
+ goto err_unregister;
+
+ return ret;
+err_unregister:
+ unregister_netdevice_notifier(&masq_dev_notifier);
+err_dec:
+ atomic_dec(&masquerade_notifier_refcount);
+ return ret;
}
EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv6_register_notifier);

@@ -181,7 +195,7 @@ void nf_nat_masquerade_ipv6_unregister_notifier(void)
if (atomic_dec_return(&masquerade_notifier_refcount) > 0)
return;

- unregister_inet6addr_notifier(&masq_inet_notifier);
+ unregister_inet6addr_notifier(&masq_inet6_notifier);
unregister_netdevice_notifier(&masq_dev_notifier);
}
EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv6_unregister_notifier);
diff --git a/net/ipv6/netfilter/nft_masq_ipv6.c b/net/ipv6/netfilter/nft_masq_ipv6.c
index dd0122f3cffe..e06c82e9dfcd 100644
--- a/net/ipv6/netfilter/nft_masq_ipv6.c
+++ b/net/ipv6/netfilter/nft_masq_ipv6.c
@@ -70,7 +70,9 @@ static int __init nft_masq_ipv6_module_init(void)
if (ret < 0)
return ret;

- nf_nat_masquerade_ipv6_register_notifier();
+ ret = nf_nat_masquerade_ipv6_register_notifier();
+ if (ret)
+ nft_unregister_expr(&nft_masq_ipv6_type);

return ret;
}
diff --git a/net/netfilter/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c
index d6bab8c3cbb0..5fd4c57c79cc 100644
--- a/net/netfilter/nft_flow_offload.c
+++ b/net/netfilter/nft_flow_offload.c
@@ -214,7 +214,9 @@ static int __init nft_flow_offload_module_init(void)
{
int err;

- register_netdevice_notifier(&flow_offload_netdev_notifier);
+ err = register_netdevice_notifier(&flow_offload_netdev_notifier);
+ if (err)
+ goto err;

err = nft_register_expr(&nft_flow_offload_type);
if (err < 0)
@@ -224,6 +226,7 @@ static int __init nft_flow_offload_module_init(void)

register_expr:
unregister_netdevice_notifier(&flow_offload_netdev_notifier);
+err:
return err;
}

--
2.17.1