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    SubjectRe: [PATCH] Audit: fix handling of 'strings' with NULL characters
    On Thu, 11 Sep 2008 17:48:39 -0400
    Eric Paris <eparis@redhat.com> 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 <eparis@redhat.com>
    >
    > ---
    >
    > 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.



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