This is a note to let you know that I've just added the patch titled
ipv4: use RCU protection in rt_is_expired()
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ipv4-use-rcu-protection-in-rt_is_expired.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit e3ed566b4ce73eef049096743cbb6f3f1a85300b
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Wed Feb 5 15:51:13 2025 +0000
ipv4: use RCU protection in rt_is_expired()
[ Upstream commit dd205fcc33d92d54eee4d7f21bb073af9bd5ce2b ]
rt_is_expired() must use RCU protection to make
sure the net structure it reads does not disappear.
Fixes: e84f84f27647 ("netns: place rt_genid into struct net")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reviewed-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Link: https://patch.msgid.link/20250205155120.1676781-6-edumazet@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index c34386a9d99b4..a2a7f2597e201 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -423,7 +423,13 @@ static inline int ip_rt_proc_init(void)
static inline bool rt_is_expired(const struct rtable *rth)
{
- return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
+ bool res;
+
+ rcu_read_lock();
+ res = rth->rt_genid != rt_genid_ipv4(dev_net_rcu(rth->dst.dev));
+ rcu_read_unlock();
+
+ return res;
}
void rt_cache_flush(struct net *net)
