From: Stephen Hemminger <stephen@networkplumber.org>
To: Michal Kubecek <mkubecek@suse.cz>
Cc: netdev@vger.kernel.org
Subject: Re: [PATCH iproute2] ip xfrm: use correct key length for netlink message
Date: Sun, 1 Oct 2017 13:48:52 -0700 [thread overview]
Message-ID: <20171001134852.5aadf10b@xeon-e3> (raw)
In-Reply-To: <20170929114105.2D971A0F6B@unicorn.suse.cz>
On Fri, 29 Sep 2017 13:41:05 +0200 (CEST)
Michal Kubecek <mkubecek@suse.cz> wrote:
> When SA is added manually using "ip xfrm state add", xfrm_state_modify()
> uses alg_key_len field of struct xfrm_algo for the length of key passed to
> kernel in the netlink message. However alg_key_len is bit length of the key
> while we need byte length here. This is usually harmless as kernel ignores
> the excess data but when the bit length of the key exceeds 512
> (XFRM_ALGO_KEY_BUF_SIZE), it can result in buffer overflow.
>
> We can simply divide by 8 here as the only place setting alg_key_len is in
> xfrm_algo_parse() where it is always set to a multiple of 8 (and there are
> already multiple places using "algo->alg_key_len / 8").
>
> Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
This looks correct applied.
prev parent reply other threads:[~2017-10-01 20:49 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-29 11:41 [PATCH iproute2] ip xfrm: use correct key length for netlink message Michal Kubecek
2017-10-01 20:48 ` Stephen Hemminger [this message]
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:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20171001134852.5aadf10b@xeon-e3 \
--to=stephen@networkplumber.org \
--cc=mkubecek@suse.cz \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* 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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.