target/linux/generic/backport-5.4/080-wireguard-0122-wireguard-device-do-not-generate-ICMP-for-non-IP-pac.patch

   1 From 49da2a610d63cef849f0095e601821ad6edfbef7 Mon Sep 17 00:00:00 2001
   2 From: "Jason A. Donenfeld" <Jason@zx2c4.com>
   3 Date: Mon, 22 Feb 2021 17:25:47 +0100
   4 Subject: [PATCH 122/124] wireguard: device: do not generate ICMP for non-IP
   5  packets
   6
   7 commit 99fff5264e7ab06f45b0ad60243475be0a8d0559 upstream.
   8
   9 If skb->protocol doesn't match the actual skb->data header, it's
  10 probably not a good idea to pass it off to icmp{,v6}_ndo_send, which is
  11 expecting to reply to a valid IP packet. So this commit has that early
  12 mismatch case jump to a later error label.
  13
  14 Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
  15 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
  16 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
  17 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
  18 ---
  19  drivers/net/wireguard/device.c | 7 ++++---
  20  1 file changed, 4 insertions(+), 3 deletions(-)
  21
  22 --- a/drivers/net/wireguard/device.c
  23 +++ b/drivers/net/wireguard/device.c
  24 @@ -138,7 +138,7 @@ static netdev_tx_t wg_xmit(struct sk_buf
  25                 else if (skb->protocol == htons(ETH_P_IPV6))
  26                         net_dbg_ratelimited("%s: No peer has allowed IPs matching %pI6\n",
  27                                             dev->name, &ipv6_hdr(skb)->daddr);
  28 -               goto err;
  29 +               goto err_icmp;
  30         }
  31
  32         family = READ_ONCE(peer->endpoint.addr.sa_family);
  33 @@ -201,12 +201,13 @@ static netdev_tx_t wg_xmit(struct sk_buf
  34
  35  err_peer:
  36         wg_peer_put(peer);
  37 -err:
  38 -       ++dev->stats.tx_errors;
  39 +err_icmp:
  40         if (skb->protocol == htons(ETH_P_IP))
  41                 icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
  42         else if (skb->protocol == htons(ETH_P_IPV6))
  43                 icmpv6_ndo_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
  44 +err:
  45 +       ++dev->stats.tx_errors;
  46         kfree_skb(skb);
  47         return ret;
  48  }