netdev - [PATCH v2 net 3/4] llc: Don't drop packet from non-root netns.

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Date: Tue, 18 Jul 2023 10:41:51 -0700
From: Kuniyuki Iwashima <kuniyu@...zon.com>
To: "David S. Miller" <davem@...emloft.net>, Eric Dumazet
	<edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>, Paolo Abeni
	<pabeni@...hat.com>, Roopa Prabhu <roopa@...dia.com>, Nikolay Aleksandrov
	<razor@...ckwall.org>
CC: "Eric W. Biederman" <ebiederm@...ssion.com>, Harry Coin
	<hcoin@...etfountain.com>, Kuniyuki Iwashima <kuniyu@...zon.com>, "Kuniyuki
 Iwashima" <kuni1840@...il.com>, <netdev@...r.kernel.org>
Subject: [PATCH v2 net 3/4] llc: Don't drop packet from non-root netns.

Now these upper layer protocol handlers can be called from llc_rcv()
as sap->rcv_func(), which is registered by llc_sap_open().

  * function which is passed to register_8022_client()
    -> no in-kernel user calls register_8022_client().

  * snap_rcv()
    `- proto->rcvfunc() : registered by register_snap_client()
       -> aarp_rcv() and atalk_rcv() drop packets from non-root netns

  * stp_pdu_rcv()
    `- garp_protos[]->rcv() : registered by stp_proto_register()
       -> garp_pdu_rcv() and br_stp_rcv() are netns-aware

So, we can safely remove the netns restriction in llc_rcv().

Fixes: e730c15519d0 ("[NET]: Make packet reception network namespace safe")
Signed-off-by: Kuniyuki Iwashima <kuniyu@...zon.com>
---
 net/llc/llc_input.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/net/llc/llc_input.c b/net/llc/llc_input.c
index c309b72a5877..7cac441862e2 100644
--- a/net/llc/llc_input.c
+++ b/net/llc/llc_input.c
@@ -163,9 +163,6 @@ int llc_rcv(struct sk_buff *skb, struct net_device *dev,
 	void (*sta_handler)(struct sk_buff *skb);
 	void (*sap_handler)(struct llc_sap *sap, struct sk_buff *skb);
 
-	if (!net_eq(dev_net(dev), &init_net))
-		goto drop;
-
 	/*
 	 * When the interface is in promisc. mode, drop all the crap that it
 	 * receives, do not try to analyse it.
-- 
2.30.2