This is a note to let you know that I've just added the patch titled
neighbour: use RCU protection in __neigh_notify()
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:
neighbour-use-rcu-protection-in-__neigh_notify.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 7621c81b2327d4856333ab1c92e86a266a07456f
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Fri Feb 7 13:58:35 2025 +0000
neighbour: use RCU protection in __neigh_notify()
[ Upstream commit becbd5850c03ed33b232083dd66c6e38c0c0e569 ]
__neigh_notify() can be called without RTNL or RCU protection.
Use RCU protection to avoid potential UAF.
Fixes: 426b5303eb43 ("[NETNS]: Modify the neighbour table code so it handles multiple network namespaces")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reviewed-by: David Ahern <dsahern@xxxxxxxxxx>
Reviewed-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Link: https://patch.msgid.link/20250207135841.1948589-4-edumazet@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 89656d180bc60..bd0251bd74a1f 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -3447,10 +3447,12 @@ static const struct seq_operations neigh_stat_seq_ops = {
static void __neigh_notify(struct neighbour *n, int type, int flags,
u32 pid)
{
- struct net *net = dev_net(n->dev);
struct sk_buff *skb;
int err = -ENOBUFS;
+ struct net *net;
+ rcu_read_lock();
+ net = dev_net_rcu(n->dev);
skb = nlmsg_new(neigh_nlmsg_size(), GFP_ATOMIC);
if (skb == NULL)
goto errout;
@@ -3463,9 +3465,11 @@ static void __neigh_notify(struct neighbour *n, int type, int flags,
goto errout;
}
rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
- return;
+ goto out;
errout:
rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
+out:
+ rcu_read_unlock();
}
void neigh_app_ns(struct neighbour *n)
