Patch "wireguard: device: do not generate ICMP for non-IP packets" has been added to the 5.11-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    wireguard: device: do not generate ICMP for non-IP packets

to the 5.11-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:
     wireguard-device-do-not-generate-icmp-for-non-ip-pac.patch
and it can be found in the queue-5.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit e8859d2db88a4545b2ab7cc4b5048e1be17ddd8f
Author: Jason A. Donenfeld <Jason@xxxxxxxxx>
Date:   Mon Feb 22 17:25:47 2021 +0100

    wireguard: device: do not generate ICMP for non-IP packets
    
    [ Upstream commit 99fff5264e7ab06f45b0ad60243475be0a8d0559 ]
    
    If skb->protocol doesn't match the actual skb->data header, it's
    probably not a good idea to pass it off to icmp{,v6}_ndo_send, which is
    expecting to reply to a valid IP packet. So this commit has that early
    mismatch case jump to a later error label.
    
    Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
    Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
    Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/wireguard/device.c b/drivers/net/wireguard/device.c
index a3ed49cd95c31..82ce757c852ee 100644
--- a/drivers/net/wireguard/device.c
+++ b/drivers/net/wireguard/device.c
@@ -138,7 +138,7 @@ static netdev_tx_t wg_xmit(struct sk_buff *skb, struct net_device *dev)
 		else if (skb->protocol == htons(ETH_P_IPV6))
 			net_dbg_ratelimited("%s: No peer has allowed IPs matching %pI6\n",
 					    dev->name, &ipv6_hdr(skb)->daddr);
-		goto err;
+		goto err_icmp;
 	}
 
 	family = READ_ONCE(peer->endpoint.addr.sa_family);
@@ -201,12 +201,13 @@ static netdev_tx_t wg_xmit(struct sk_buff *skb, struct net_device *dev)
 
 err_peer:
 	wg_peer_put(peer);
-err:
-	++dev->stats.tx_errors;
+err_icmp:
 	if (skb->protocol == htons(ETH_P_IP))
 		icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
 	else if (skb->protocol == htons(ETH_P_IPV6))
 		icmpv6_ndo_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
+err:
+	++dev->stats.tx_errors;
 	kfree_skb(skb);
 	return ret;
 }