Re: [PATCH net-next v2] net: WireGuard secure network tunnel

From: Dmitry Vyukov <dvyukov@google.com>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: netdev <netdev@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	David Miller <davem@davemloft.net>,
	Greg KH <gregkh@linuxfoundation.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Herbert Xu <herbert@gondor.apana.org.au>,
	"open list:HARDWARE RANDOM NUMBER GENERATOR CORE" 
	<linux-crypto@vger.kernel.org>
Subject: Re: [PATCH net-next v2] net: WireGuard secure network tunnel
Date: Thu, 19 Dec 2019 11:49:23 +0100	[thread overview]
Message-ID: <CACT4Y+YfBDvQHdK24ybyyy5p07MXNMnLA7+gq9axq-EizN6jhA@mail.gmail.com> (raw)
In-Reply-To: <CAHmME9qUWr69o0r+Mtm8tRSeQq3P780DhWAhpJkNWBfZ+J5OYA@mail.gmail.com>

On Thu, Dec 19, 2019 at 11:11 AM Jason A. Donenfeld <Jason@zx2c4.com> wrote:
>
> On Thu, Dec 19, 2019 at 11:07 AM Jason A. Donenfeld <Jason@zx2c4.com> wrote:
> >
> > On Thu, Dec 19, 2019 at 10:35 AM Dmitry Vyukov <dvyukov@google.com> wrote:
> > That's exciting about syzcaller having at it with WireGuard. Is there
> > some place where I can "see" it fuzzing WireGuard, or do I just wait
> > for the bug reports to come rolling in?
>
> Ahh, found it: https://storage.googleapis.com/syzkaller/cover/ci-upstream-net-kasan-gce.html
> Looks like we're at 1% and counting. :)

Yes, that's it. But that's mostly stray coverage.
wg_netdevice_notification I guess mostly because it tested _other_ device types.
And a bit of netlink because it sends random garbage into netlink.

For netlink part it would require something along these lines:
https://github.com/google/syzkaller/blob/master/sys/linux/socket_netlink_generic_devlink.txt
https://github.com/google/syzkaller/blob/master/sys/linux/socket_netlink_crypto.txt
https://github.com/google/syzkaller/blob/master/sys/linux/socket_netlink_generic_fou.txt
https://github.com/google/syzkaller/blob/master/sys/linux/socket_netlink_generic_seg6.txt

And for device setup, harder to say. Either pre-create one here:
https://github.com/google/syzkaller/blob/79b211f74b08737aeb4934c6ff69a263b3c38013/executor/common_linux.h#L668
or teach it how to create them on the fly or both or something else.

Probably some wire packet formats here:
https://github.com/google/syzkaller/blob/79b211f74b08737aeb4934c6ff69a263b3c38013/sys/linux/vnet.txt