[patch 3/5] Apply the PG_sensitive flag to audit subsystem

[patch 3/5] Apply the PG_sensitive flag to audit subsystem

[Larry H.]

This patch deploys the use of the PG_sensitive page allocator flag
within the audit subsystem. It's not necessarily a high profile
target for use of this flag, but could be expected to contain
potentially sensitive information under some circumstances.

Signed-off-by: Larry H. <research@subreption.com>

---
 kernel/audit.c |    3 +++
 1 file changed, 3 insertions(+)

Index: linux-2.6/kernel/audit.c
===================================================================
--- linux-2.6.orig/kernel/audit.c
+++ linux-2.6/kernel/audit.c
@@ -1061,6 +1061,9 @@ static struct audit_buffer * audit_buffe
 	}
 	spin_unlock_irqrestore(&audit_freelist_lock, flags);
 
+	if (!(gfp_mask & GFP_SENSITIVE))
+		gfp_mask |= GFP_SENSITIVE;
+
 	if (!ab) {
 		ab = kmalloc(sizeof(*ab), gfp_mask);
 		if (!ab)

Re: [patch 3/5] Apply the PG_sensitive flag to audit subsystem

[Olaf Titz]

> +	if (!(gfp_mask & GFP_SENSITIVE))
> +		gfp_mask |= GFP_SENSITIVE;
> +

The condition is unnecessary. Just do the |= in all cases.

Olaf

Re: [patch 3/5] Apply the PG_sensitive flag to audit subsystem

[Linus Torvalds]

On Wed, 20 May 2009, Larry H. wrote:
>
> +	if (!(gfp_mask & GFP_SENSITIVE))
> +		gfp_mask |= GFP_SENSITIVE;

WTF?

Why is this different from just "gfp_mask |= GFP_SENSITIVE;"

		Linus

Re: [patch 3/5] Apply the PG_sensitive flag to audit subsystem

[Larry H.]

On 10:21 Sat 30 May     , Linus Torvalds wrote:
> 
> 
> On Wed, 20 May 2009, Larry H. wrote:
> >
> > +	if (!(gfp_mask & GFP_SENSITIVE))
> > +		gfp_mask |= GFP_SENSITIVE;
> 
> WTF?

Indeed.

> Why is this different from just "gfp_mask |= GFP_SENSITIVE;"

Blame anal retentiveness at the time of writing that. Surely the test
should be ditched. Looking back at that, I honestly think there might be a
place to plug the flag (in the caller) instead of doing that. I don't
think there are many places to do it, so this particular patch from the
set can be ditched and rewritten (if you want to take the selective
clearing road...)

	Larry