From: Dan Rosenberg <drosenberg@vsecurity.com>
To: Valdis.Kletnieks@vt.edu
Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
linux-security-module@vger.kernel.org, jmorris@namei.org,
eric.dumazet@gmail.com, tgraf@infradead.org,
eugeneteo@kernel.org, kees.cook@canonical.com, mingo@elte.hu,
davem@davemloft.net, a.p.zijlstra@chello.nl,
akpm@linux-foundation.org
Subject: Re: [PATCH v3] kptr_restrict for hiding kernel pointers
Date: Mon, 20 Dec 2010 18:01:28 -0500 [thread overview]
Message-ID: <1292886088.4061.3.camel@dan> (raw)
In-Reply-To: <50259.1292883991@localhost>
On Mon, 2010-12-20 at 17:26 -0500, Valdis.Kletnieks@vt.edu wrote:
> On Sat, 18 Dec 2010 12:20:34 EST, Dan Rosenberg said:
>
> > @@ -1035,6 +1038,26 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
> > return buf + vsnprintf(buf, end - buf,
> > ((struct va_format *)ptr)->fmt,
> > *(((struct va_format *)ptr)->va));
> > + case 'K':
> > + /*
> > + * %pK cannot be used in IRQ context because it tests
> > + * CAP_SYSLOG.
> > + */
> > + if (in_irq() || in_serving_softirq() || in_nmi())
> > + WARN_ONCE(1, "%%pK used in interrupt context.\n");
>
> Should this then continue on and test CAP_SYSLOG anyhow, or should it
> return a "" or or "<invalid>" or something?
This is a valid point. I'll resend a new version shortly that defaults
to zeroing pointers if it's used incorrectly without relying on
capability checks.
Thanks,
Dan
prev parent reply other threads:[~2010-12-20 23:01 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-18 17:20 [PATCH v3] kptr_restrict for hiding kernel pointers Dan Rosenberg
2010-12-18 18:27 ` Kees Cook
2010-12-18 21:07 ` Eric Paris
2010-12-18 21:10 ` Eric Paris
2010-12-20 22:26 ` Valdis.Kletnieks
2010-12-20 23:01 ` Dan Rosenberg [this message]
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