Re: [PATCH] squash: review-updates

[Eric Paris <eparis@redhat.com>]

If you know the buf len, you can just use audit_log_n_untrusted_string()
I think....

On Tue, 2014-01-07 at 12:44 -0800, William Roberts wrote:
> Signed-off-by: William Roberts <wroberts@tresys.com>
> ---
>  kernel/auditsc.c |   19 +++++++++++++++----
>  1 file changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index a4c2003..9ba1f2a 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -1292,9 +1292,20 @@ static void audit_log_cmdline(struct audit_buffer *ab, struct task_struct *tsk,
>  		if (!buf)
>  			goto out;
>  		res = get_cmdline(tsk, buf, PATH_MAX);
> -		/* Ensure NULL terminated */
> -		if (buf[res-1] != '\0')
> -			buf[res-1] = '\0';
> +		if (res == 0) {
> +			kfree(buf);
> +			goto out;
> +		}
> +		/*
> +		 * Ensure NULL terminated but don't clobber the end
> +		 * unless the buffer is full. Worst case you end up
> +		 * with 2 null bytes ending it. By doing it this way
> +		 * one avoids additional branching. One checking if the
> +		 * end is null and another to check if their should be
> +		 * an increment before setting the null byte.
> +		 */
> +		res += res < PATH_MAX;
> +		buf[res-1] = '\0';
>  		context->cmdline = buf;
>  	}
>  	msg = context->cmdline;
> @@ -1333,8 +1344,8 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
>  			 context->name_count);
>  
>  	audit_log_task_info(ab, tsk);
> -	audit_log_cmdline(ab, tsk, context);
>  	audit_log_key(ab, context->filterkey);
> +	audit_log_cmdline(ab, tsk, context);
>  	audit_log_end(ab);
>  
>  	for (aux = context->aux; aux; aux = aux->next) {