From: Eric Dumazet <edumazet@google.com>
Date: Fri, 7 Feb 2025 13:58:33 +0000 (+0000)
Subject: ndisc: ndisc_send_redirect() must use dev_get_by_index_rcu()
X-Git-Tag: v5.15.179~283
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=80f70686857e509dc5fb06be3130a586f59516d2;p=thirdparty%2Fkernel%2Fstable.git

ndisc: ndisc_send_redirect() must use dev_get_by_index_rcu()

[ Upstream commit 48145a57d4bbe3496e8e4880b23ea6b511e6e519 ]

ndisc_send_redirect() is called under RCU protection, not RTNL.

It must use dev_get_by_index_rcu() instead of __dev_get_by_index()

Fixes: 2f17becfbea5 ("vrf: check the original netdevice for generating redirect")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stephen Suryaputra <ssuryaextr@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250207135841.1948589-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index d56e80741c5ba..63c1420c58249 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1619,7 +1619,7 @@ void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
 	bool ret;
 
 	if (netif_is_l3_master(skb->dev)) {
-		dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
+		dev = dev_get_by_index_rcu(dev_net(skb->dev), IPCB(skb)->iif);
 		if (!dev)
 			return;
 	}