Development discussion of WireGuard
 help / color / mirror / Atom feed
From: "Jason A. Donenfeld" <>
To: Nikolay Aleksandrov <>
Cc: Netdev <>,
	Daniel Borkmann <>,
	 Martynas Pumputis <>,
	WireGuard mailing list <>,
	 Jakub Kicinski <>,
	David Miller <>,
	stable <>
Subject: Re: [PATCH net 1/2] wireguard: device: fix metadata_dst xmit null pointer dereference
Date: Thu, 14 Apr 2022 13:58:04 +0200	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

Hi Nikolay,

On Thu, Apr 14, 2022 at 12:45 PM Nikolay Aleksandrov
<> wrote:
> When we try to transmit an skb with md_dst attached through wireguard
> we hit a null pointer dereference[1] in wg_xmit() due to the use of
> dst_mtu() which calls into dst_blackhole_mtu() which in turn tries to
> dereference dst->dev. Since wireguard doesn't use md_dsts we should use
> skb_valid_dst() which checks for DST_METADATA flag and if it's set then
> fallback to wireguard's device mtu. That gives us the best chance of
> transmitting the packet, otherwise if the blackhole netdev is used we'd
> get ETH_MIN_MTU.

Thanks for the patch. Will queue up this patch #1 in the wireguard
tree and send it out to net.git not before too long.


  parent reply	other threads:[~2022-04-14 11:58 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-14 10:44 [PATCH net 0/2] " Nikolay Aleksandrov
2022-04-14 10:44 ` [PATCH net 1/2] " Nikolay Aleksandrov
2022-04-14 11:28   ` Daniel Borkmann
2022-04-14 11:58   ` Jason A. Donenfeld [this message]
2022-04-14 10:44 ` [PATCH net 2/2] wireguard: selftests: add metadata_dst xmit selftest Nikolay Aleksandrov
2022-04-14 12:06   ` Jason A. Donenfeld
2022-04-14 12:12     ` Nikolay Aleksandrov
2022-04-14 12:24       ` Jason A. Donenfeld

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).