From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 5 Feb 2014 15:30:27 -0500 From: Nick Bowler To: Paul Gortmaker CC: , , Herbert Xu Subject: Re: [v2.6.34-stable 004/213] crypto: ghash - Avoid null pointer dereference if no key is set Message-ID: <20140205203027.GA23845@elliptictech.com> References: <1391630568-49251-1-git-send-email-paul.gortmaker@windriver.com> <1391630568-49251-5-git-send-email-paul.gortmaker@windriver.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1391630568-49251-5-git-send-email-paul.gortmaker@windriver.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: On 2014-02-05 14:59 -0500, Paul Gortmaker wrote: > From: Nick Bowler > > ------------------- > This is a commit scheduled for the next v2.6.34 longterm release. > http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git > If you see a problem with using this for longterm, please comment. > ------------------- > > commit 7ed47b7d142ec99ad6880bbbec51e9f12b3af74c upstream. > > 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 unprivileged userspace through the > AF_ALG interface by simply writing to the socket without setting a key. After all this time, I see this patch still manages to find its way, occasionally, into the patch queue for older -stable. :) It should be harmless to apply, but this patch doesn't actually fix any real problem on kernels previous to 2.6.38 because the AF_ALG userspace interface does not exist in these kernels. Cheers, -- Nick Bowler, Elliptic Technologies (http://www.elliptictech.com/)