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Message-ID: <20241017174109.85717-5-stefan.wiehler@nokia.com>
Date: Thu, 17 Oct 2024 19:37:46 +0200
From: Stefan Wiehler <stefan.wiehler@...ia.com>
To: "David S . Miller" <davem@...emloft.net>,
David Ahern <dsahern@...nel.org>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>
Cc: netdev@...r.kernel.org,
linux-kernel@...r.kernel.org,
Stefan Wiehler <stefan.wiehler@...ia.com>
Subject: [PATCH net v6 04/10] ip6mr: Lock RCU before ip6mr_get_table() call in ip6mr_get_route()
When IPV6_MROUTE_MULTIPLE_TABLES is enabled, multicast routing tables
must be read under RCU or RTNL lock.
Signed-off-by: Stefan Wiehler <stefan.wiehler@...ia.com>
Fixes: d1db275dd3f6 ("ipv6: ip6mr: support multiple tables")
---
net/ipv6/ip6mr.c | 21 ++++++++++++---------
1 file changed, 12 insertions(+), 9 deletions(-)
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 968642bde8f8..017f9e31edfb 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -2303,11 +2303,13 @@ int ip6mr_get_route(struct net *net, struct sk_buff *skb, struct rtmsg *rtm,
struct mfc6_cache *cache;
struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
+ rcu_read_lock();
mrt = ip6mr_get_table(net, RT6_TABLE_DFLT);
- if (!mrt)
- return -ENOENT;
+ if (!mrt) {
+ err = -ENOENT;
+ goto out;
+ }
- rcu_read_lock();
cache = ip6mr_cache_find(mrt, &rt->rt6i_src.addr, &rt->rt6i_dst.addr);
if (!cache && skb->dev) {
int vif = ip6mr_find_vif(mrt, skb->dev);
@@ -2325,15 +2327,15 @@ int ip6mr_get_route(struct net *net, struct sk_buff *skb, struct rtmsg *rtm,
dev = skb->dev;
if (!dev || (vif = ip6mr_find_vif(mrt, dev)) < 0) {
- rcu_read_unlock();
- return -ENODEV;
+ err = -ENODEV;
+ goto out;
}
/* really correct? */
skb2 = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
if (!skb2) {
- rcu_read_unlock();
- return -ENOMEM;
+ err = -ENOMEM;
+ goto out;
}
NETLINK_CB(skb2).portid = portid;
@@ -2355,12 +2357,13 @@ int ip6mr_get_route(struct net *net, struct sk_buff *skb, struct rtmsg *rtm,
iph->daddr = rt->rt6i_dst.addr;
err = ip6mr_cache_unresolved(mrt, vif, skb2, dev);
- rcu_read_unlock();
- return err;
+ goto out;
}
err = mr_fill_mroute(mrt, skb, &cache->_c, rtm);
+
+out:
rcu_read_unlock();
return err;
}
--
2.42.0
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