From mboxrd@z Thu Jan  1 00:00:00 1970
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From: Andi Kleen <andi@firstfloor.org>
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Date: Mon, 19 Sep 2011 11:29:28 -0700
In-Reply-To: <CA+55aFxXS9z=NwoYug+qGoYufqN-6dCo4fm5ggTsoDonsMi4Dw@mail.gmail.com>
	(Linus Torvalds's message of "Mon, 19 Sep 2011 09:40:19 -0700")
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Subject: [kernel-hardening] Re: [Security] [PATCH 2/2] taskstats: restrict access to user
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Balbir Singh <bsingharora@gmail.com>, Vasiliy Kulikov <segoon@openwall.com>, Shailabh Nagar <nagar@us.ibm.com>, linux-kernel@vger.kernel.org, security@kernel.org, Eric Paris <eparis@redhat.com>, Stephen Wilson <wilsons@start.ca>, KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>, David Rientjes <rientjes@google.com>, Andrew Morton <akpm@linux-foundation.org>, Balbir Singh <balbir@linux.vnet.ibm.com>, kernel-hardening@lists.openwall.com
List-ID: <kernel-hardening.lists.openwall.com>

Linus Torvalds <torvalds@linux-foundation.org> writes:
>  	rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], mask);
> diff --git a/kernel/tsacct.c b/kernel/tsacct.c
> index 24dc60d9fa1f..110ca5a03bd6 100644
> --- a/kernel/tsacct.c
> +++ b/kernel/tsacct.c
> @@ -78,6 +78,7 @@ void bacct_add_tsk(struct taskstats *stats, struct task_struct *tsk)
>  
>  #define KB 1024

Needs to be 1024ULL, because the counters are 64bit.

>  #define MB (1024*KB)
> +#define KB_MASK (~(KB-1))

Otherwise you lose the upper 32bits here.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only