From: Kees Cook <keescook@chromium.org>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kuba@kernel.org, pablo@netfilter.org, davem@davemloft.net,
netdev@vger.kernel.org
Subject: Re: [PATCH net 3/3] wireguard: netlink: avoid variable-sized memcpy on sockaddr
Date: Fri, 16 Sep 2022 08:04:01 -0700 [thread overview]
Message-ID: <202209160802.60021AF07@keescook> (raw)
In-Reply-To: <20220916143740.831881-4-Jason@zx2c4.com>
On Fri, Sep 16, 2022 at 03:37:40PM +0100, Jason A. Donenfeld wrote:
> Doing a variable-sized memcpy is slower, and the compiler isn't smart
> enough to turn this into a constant-size assignment.
>
> Further, Kees' latest fortified memcpy will actually bark, because the
> destination pointer is type sockaddr, not explicitly sockaddr_in or
> sockaddr_in6, so it thinks there's an overflow:
>
> memcpy: detected field-spanning write (size 28) of single field
> "&endpoint.addr" at drivers/net/wireguard/netlink.c:446 (size 16)
>
> Fix this by just assigning by using explicit casts for each checked
> case.
>
> Cc: Kees Cook <keescook@chromium.org>
> Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Oh, also, please include reporter details:
Reported-by: syzbot+a448cda4dba2dac50de5@syzkaller.appspotmail.com
--
Kees Cook
next prev parent reply other threads:[~2022-09-16 15:04 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-16 14:37 [PATCH net 0/3] wireguard patches for 6.0-rc6 Jason A. Donenfeld
2022-09-16 14:37 ` [PATCH net 1/3] wireguard: ratelimiter: disable timings test by default Jason A. Donenfeld
2022-09-16 14:37 ` [PATCH net 2/3] wireguard: selftests: do not install headers on UML Jason A. Donenfeld
2022-09-16 14:37 ` [PATCH net 3/3] wireguard: netlink: avoid variable-sized memcpy on sockaddr Jason A. Donenfeld
2022-09-16 15:02 ` Kees Cook
2022-09-16 15:04 ` Kees Cook [this message]
2022-09-20 1:20 ` [PATCH net 0/3] wireguard patches for 6.0-rc6 Jakub Kicinski
2022-09-20 6:47 ` Jason A. Donenfeld
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