linux-kernel - Re: [PATCH] net/xfrm: Fix lookups for states with spi == 0

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20180502091125.jnzaaazh67z4ihyf@gondor.apana.org.au>
Date:   Wed, 2 May 2018 17:11:25 +0800
From:   Herbert Xu <herbert@...dor.apana.org.au>
To:     Dmitry Safonov <dima@...sta.com>
Cc:     linux-kernel@...r.kernel.org, 0x7f454c46@...il.com,
        Steffen Klassert <steffen.klassert@...unet.com>,
        "David S. Miller" <davem@...emloft.net>, netdev@...r.kernel.org
Subject: Re: [PATCH] net/xfrm: Fix lookups for states with spi == 0

On Wed, May 02, 2018 at 03:02:20AM +0100, Dmitry Safonov wrote:
> It seems to be a valid use case to add xfrm state without
> Security Parameter Indexes (SPI) value associated:
> ip xfrm state add src $src dst $dst proto $proto mode $mode sel src $src dst $dst $algo
> 
> The bad thing is that it's currently impossible to get/delete the state
> without SPI: __xfrm_state_insert() obviously doesn't add hash for zero
> SPI in xfrm.state_byspi, and xfrm_user_state_lookup() will fail as
> xfrm_state_lookup() does lookups by hash.
> 
> It also isn't possible to workaround from userspace as
> xfrm_id_proto_match() will be always true for ah/esp/comp protos.
> 
> So, don't try looking up by hash if SPI == 0.
> 
> Cc: Steffen Klassert <steffen.klassert@...unet.com>
> Cc: Herbert Xu <herbert@...dor.apana.org.au>
> Cc: "David S. Miller" <davem@...emloft.net>
> Cc: netdev@...r.kernel.org
> Signed-off-by: Dmitry Safonov <dima@...sta.com>

A zero SPI is illegal for many IPsec protocols because that value
is used for other purposes, e.g., IKE encapsulation.

Cheers,
-- 
Email: Herbert Xu <herbert@...dor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt