From: Paolo Abeni <pabeni@redhat.com>
To: netdev@vger.kernel.org
Cc: David Ahern <dsahern@gmail.com>, "David S. Miller" <davem@davemloft.net>
Subject: [PATCH net v2 1/2] ipv6: route: enforce RCU protection in rt6_update_exception_stamp_rt()
Date: Thu, 21 Feb 2019 11:19:41 +0100 [thread overview]
Message-ID: <fe784e447b956d111d61d8dbc3386d7bb95a8d89.1550684182.git.pabeni@redhat.com> (raw)
In-Reply-To: <cover.1550684182.git.pabeni@redhat.com>
We must access rt6_info->from under RCU read lock: move the
dereference under such lock, with proper annotation.
v1 -> v2:
- avoid using multiple, racy, fetch operations for rt->from
Fixes: a68886a69180 ("net/ipv6: Make from in rt6_info rcu protected")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
net/ipv6/route.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index bd09abd1fb22..1597a3746b40 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1610,15 +1610,15 @@ static int rt6_remove_exception_rt(struct rt6_info *rt)
static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
{
struct rt6_exception_bucket *bucket;
- struct fib6_info *from = rt->from;
struct in6_addr *src_key = NULL;
struct rt6_exception *rt6_ex;
-
- if (!from ||
- !(rt->rt6i_flags & RTF_CACHE))
- return;
+ struct fib6_info *from;
rcu_read_lock();
+ from = rcu_dereference(rt->from);
+ if (!from || !(rt->rt6i_flags & RTF_CACHE))
+ goto unlock;
+
bucket = rcu_dereference(from->rt6i_exception_bucket);
#ifdef CONFIG_IPV6_SUBTREES
@@ -1637,6 +1637,7 @@ static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
if (rt6_ex)
rt6_ex->stamp = jiffies;
+unlock:
rcu_read_unlock();
}
--
2.20.1
next prev parent reply other threads:[~2019-02-21 10:20 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-21 10:19 [PATCH net v2 0/2] ipv6: route: enforce RCU protection for fib6_info->from Paolo Abeni
2019-02-21 10:19 ` Paolo Abeni [this message]
2019-02-21 14:57 ` [PATCH net v2 1/2] ipv6: route: enforce RCU protection in rt6_update_exception_stamp_rt() David Ahern
2019-02-21 10:19 ` [PATCH net v2 2/2] ipv6: route: enforce RCU protection in ip6_route_check_nh_onlink() Paolo Abeni
2019-02-21 14:57 ` David Ahern
2019-02-21 17:54 ` [PATCH net v2 0/2] ipv6: route: enforce RCU protection for fib6_info->from David Miller
2019-02-22 2:45 ` David Ahern
2019-02-22 5:32 ` David Miller
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