From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [PATCH] Audit: fix handling of 'strings' with NULL characters Date: Thu, 11 Sep 2008 17:09:20 -0700 Message-ID: <20080911170920.e88e7bc5.akpm@linux-foundation.org> References: <1221169719.2952.14.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1221169719.2952.14.camel@localhost.localdomain> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-audit-bounces@redhat.com Errors-To: linux-audit-bounces@redhat.com To: Eric Paris Cc: mitr@redhat.com, linux-kernel@vger.kernel.org, linux-audit@redhat.com, viro@zeniv.linux.org.uk List-Id: linux-audit@redhat.com On Thu, 11 Sep 2008 17:48:39 -0400 Eric Paris wrote: > currently audit_log_n_untrustedstring() uses > audit_string_contains_control() to check if the 'string' has any control > characters. If the 'string' has an embedded NULL > audit_string_contains_control() will return that the data has no control > characters and will then pass the string to audit_log_n_string with the > total length, not the length up to the first NULL. audit_log_n_string > does a memcpy of the entire length and so the actual audit record > emitted may then contain a NULL and then whatever random memory is after > the NULL. > > Since we want to log the entire octet stream (if we can't trust the data > to be a string we can't trust that a NULL isn't actually a part of it) > we should just consider NULL as a control character. If the caller is > certain they want to stop at the first NULL they should be using > audit_log_untrustedstring. > > Signed-off-by: Eric Paris > > --- > > Miloslav, this is also going to take care of nulls in the TTY_AUDIT_USER > message from userspace. Is it going to be common to have control > characters on that code path as well? Do you want to change > audit_receive_msg() to also use the hex encoding directly instead of the > _n_untrustedstring interface? OK, I am now officially confused about the relationship between this patch, Miloslav's two patches and 2.6.27/2.6.26/2.6.25. Think I'll go into hiding for a while - please wake us up when it's all sorted out.