Re: [PATCH] net/bridge: Add missing in6_dev_put in br_validate_ipv6

From: Eric Dumazet
Date: Mon Jul 06 2015 - 07:16:52 EST


On Mon, 2015-07-06 at 11:35 +0100, Julien Grall wrote:

> __in6_dev_get requires to hold rcu_read_lock or RTNL. My knowledge on
> this code is very limited. Are we sure that one this lock is hold? At
> first glance, I wasn't able to find one.

You could play it safe ;)

diff --git a/net/bridge/br_netfilter_ipv6.c b/net/bridge/br_netfilter_ipv6.c
index 6d12d2675c80..90e8ccc21cc5 100644
--- a/net/bridge/br_netfilter_ipv6.c
+++ b/net/bridge/br_netfilter_ipv6.c
@@ -104,10 +104,12 @@ int br_validate_ipv6(struct sk_buff *skb)
{
const struct ipv6hdr *hdr;
struct net_device *dev = skb->dev;
- struct inet6_dev *idev = in6_dev_get(skb->dev);
+ struct inet6_dev *idev;
u32 pkt_len;
u8 ip6h_len = sizeof(struct ipv6hdr);

+ rcu_read_lock();
+ idev = __in6_dev_get(dev);
if (!pskb_may_pull(skb, ip6h_len))
goto inhdr_error;

@@ -140,11 +142,13 @@ int br_validate_ipv6(struct sk_buff *skb)
/* No IP options in IPv6 header; however it should be
* checked if some next headers need special treatment
*/
+ rcu_read_unlock();
return 0;

inhdr_error:
IP6_INC_STATS_BH(dev_net(dev), idev, IPSTATS_MIB_INHDRERRORS);
drop:
+ rcu_read_unlock();
return -1;
}



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/