This is a note to let you know that I've just added the patch titled
vrf: use RCU protection in l3mdev_l3_out()
to the 6.13-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:
vrf-use-rcu-protection-in-l3mdev_l3_out.patch
and it can be found in the queue-6.13 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 42b263ac5a508f8cac0928724307f191f7cc8fc0
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Fri Feb 7 13:58:38 2025 +0000
vrf: use RCU protection in l3mdev_l3_out()
[ Upstream commit 6d0ce46a93135d96b7fa075a94a88fe0da8e8773 ]
l3mdev_l3_out() can be called without RCU being held:
raw_sendmsg()
ip_push_pending_frames()
ip_send_skb()
ip_local_out()
__ip_local_out()
l3mdev_ip_out()
Add rcu_read_lock() / rcu_read_unlock() pair to avoid
a potential UAF.
Fixes: a8e3e1a9f020 ("net: l3mdev: Add hook to output path")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reviewed-by: David Ahern <dsahern@xxxxxxxxxx>
Reviewed-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Link: https://patch.msgid.link/20250207135841.1948589-7-edumazet@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/net/l3mdev.h b/include/net/l3mdev.h
index 2d6141f28b530..f7fe796e8429a 100644
--- a/include/net/l3mdev.h
+++ b/include/net/l3mdev.h
@@ -198,10 +198,12 @@ struct sk_buff *l3mdev_l3_out(struct sock *sk, struct sk_buff *skb, u16 proto)
if (netif_is_l3_slave(dev)) {
struct net_device *master;
+ rcu_read_lock();
master = netdev_master_upper_dev_get_rcu(dev);
if (master && master->l3mdev_ops->l3mdev_l3_out)
skb = master->l3mdev_ops->l3mdev_l3_out(master, sk,
skb, proto);
+ rcu_read_unlock();
}
return skb;
