From: Nick Bowler <nbowler@elliptictech.com>
To: linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Herbert Xu <herbert@gondor.hengli.com.au>,
"David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH] crypto: ghash: Avoid null pointer dereference if no key is set.
Date: Fri, 14 Oct 2011 13:13:58 -0400 [thread overview]
Message-ID: <20111014171358.GA15626@elliptictech.com> (raw)
In-Reply-To: <1318603040-1360-1-git-send-email-nbowler@elliptictech.com>
On 2011-10-14 10:37 -0400, Nick Bowler wrote:
> The ghash_update function passes a pointer to gf128mul_4k_lle which will
> be NULL if ghash_setkey is not called or if the most recent call to
> ghash_setkey failed to allocate memory. This causes an oops. Fix this
> up by returning an error code in the null case.
>
> This is trivially triggered from unpriviliged userspace through the
> AF_ALG interface by simply writing to the socket without setting a key.
It looks like this can also happen in ghash_final if an evil user calls
setkey, update with a length that's not a multiple of the block size,
then setkey again (this time failing due to an allocation failure) then
final. Thus, I suppose that final needs the same check.
v2 forthcoming...
--
Nick Bowler, Elliptic Technologies (http://www.elliptictech.com/)
next prev parent reply other threads:[~2011-10-14 17:14 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-14 14:37 [PATCH] crypto: ghash: Avoid null pointer dereference if no key is set Nick Bowler
2011-10-14 17:13 ` Nick Bowler [this message]
2011-10-14 17:53 ` [PATCH v2] " Nick Bowler
2011-10-20 12:19 ` Herbert Xu
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