target/linux/generic/backport-5.4/080-wireguard-0121-wireguard-device-do-not-generate-ICMP-for-non-IP-pac.patch

   1 From 0000000000000000000000000000000000000000 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] wireguard: device: do not generate ICMP for non-IP packets
   5
   6 commit 99fff5264e7ab06f45b0ad60243475be0a8d0559 upstream.
   7
   8 If skb->protocol doesn't match the actual skb->data header, it's
   9 probably not a good idea to pass it off to icmp{,v6}_ndo_send, which is
  10 expecting to reply to a valid IP packet. So this commit has that early
  11 mismatch case jump to a later error label.
  12
  13 Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
  14 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
  15 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
  16 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
  17 ---
  18  drivers/net/wireguard/device.c | 7 ++++---
  19  1 file changed, 4 insertions(+), 3 deletions(-)
  20
  21 --- a/drivers/net/wireguard/device.c
  22 +++ b/drivers/net/wireguard/device.c
  23 @@ -138,7 +138,7 @@ static netdev_tx_t wg_xmit(struct sk_buf
  24                 else if (skb->protocol == htons(ETH_P_IPV6))
  25                         net_dbg_ratelimited("%s: No peer has allowed IPs matching %pI6\n",
  26                                             dev->name, &ipv6_hdr(skb)->daddr);
  27 -               goto err;
  28 +               goto err_icmp;
  29         }
  30
  31         family = READ_ONCE(peer->endpoint.addr.sa_family);
  32 @@ -201,12 +201,13 @@ static netdev_tx_t wg_xmit(struct sk_buf
  33
  34  err_peer:
  35         wg_peer_put(peer);
  36 -err:
  37 -       ++dev->stats.tx_errors;
  38 +err_icmp:
  39         if (skb->protocol == htons(ETH_P_IP))
  40                 icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
  41         else if (skb->protocol == htons(ETH_P_IPV6))
  42                 icmpv6_ndo_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
  43 +err:
  44 +       ++dev->stats.tx_errors;
  45         kfree_skb(skb);
  46         return ret;
  47  }