From: Ingo Molnar <mingo@elte.hu>
To: Dan Rosenberg <drosenberg@vsecurity.com>
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,
davem@davemloft.net, a.p.zijlstra@chello.nl,
akpm@linux-foundation.org, eparis@parisplace.org
Subject: Re: [PATCH v5] kptr_restrict for hiding kernel pointers
Date: Wed, 22 Dec 2010 18:13:07 +0100 [thread overview]
Message-ID: <20101222171307.GA25611@elte.hu> (raw)
In-Reply-To: <1293037246.9820.236.camel@dan>
* Dan Rosenberg <drosenberg@vsecurity.com> wrote:
> + case 'K':
> + /*
> + * %pK cannot be used in IRQ context because its test
> + * for CAP_SYSLOG would be meaningless.
> + */
> + if (in_irq() || in_serving_softirq() || in_nmi())
> + WARN_ONCE(1, "%%pK used in interrupt context.\n");
Hm, that bit looks possibly broken - some useful warning in irq context could print
a pointer into the syslog and this would generate a second warning? That probably
would crash as it recurses back into the printk code?
Instead a warning could be inserted into the generated output instead, for example
'pK-error' (carefully staying within pointer length limits).
Also, it would be nice to see a couple of actual %pK usage sites submitted as well -
instead of this pure infrastructure patch.
Ingo
next prev parent reply other threads:[~2010-12-22 17:13 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-22 17:00 [PATCH v5] kptr_restrict for hiding kernel pointers Dan Rosenberg
2010-12-22 17:13 ` Ingo Molnar [this message]
2010-12-22 17:17 ` Dan Rosenberg
2010-12-22 17:19 ` Dan Rosenberg
2010-12-22 21:43 ` Valdis.Kletnieks
2010-12-22 17:35 ` Dan Rosenberg
2010-12-22 21:26 ` Ingo Molnar
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