[PATCH 1/2] audit: fix NUL handling in untrusted strings

[Andrew Morton]

On Thu, 11 Sep 2008 00:23:38 +0200
Miloslav Trma__ <mitr at redhat.com> wrote:

> audit_string_contains_control() stops checking at the first NUL byte.
> If audit_string_contains_control() returns FALSE,
> audit_log_n_untrustedstring() submits the complete string - including
> the NUL byte and all following bytes, up to the specified maximum length
> - to audit_log_n_string(), which copies the data unchanged into the
> audit record.
> 
> The audit record can thus contain a NUL byte (and some unchecked data
> after that).  Because the user-space audit daemon treats audit records
> as NUL-terminated strings, an untrusted string that is shorter than the
> specified maximum length effectively terminates the audit record.
> 
> This patch modifies audit_log_n_untrustedstring() to only log the data
> before the first NUL byte, if any.

It's unclear how serious this problem is.  Do you believe that it is
sufficiently serious to warrant merging these fixes into 2.6.27? 
2.6.26.x?  2.6.25.x?

Thanks.