From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Howells <dhowells@redhat.com>
Subject: Re: [patch 2/9] fs: Add missing rcu protection for __task_cred() in sys_ioprio_get
Date: Fri, 11 Dec 2009 13:46:02 +0000
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References: <20091210004703.067454615@linutronix.de> <20091210001308.247025548@linutronix.de>
Cc: dhowells@redhat.com, LKML <linux-kernel@vger.kernel.org>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	Dipankar Sarma <dipankar@in.ibm.com>,
	Ingo Molnar <mingo@elte.hu>,
	Peter Zijlstra <peterz@infradead.org>,
	Oleg Nesterov <oleg@tv-sign.ru>,
	Al Viro <viro@zeniv.linux.org.uk>,
	James Morris <jmorris@namei.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	linux-security-module@vger.kernel.org,
	linux-fsdevel@vger.kernel.org
To: Thomas Gleixner <tglx@linutronix.de>
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Thomas Gleixner <tglx@linutronix.de> wrote:

> sys_ioprio_get() accesses __task_cred() without being in a RCU read
> side critical section. tasklist_lock is not protecting that when
> CONFIG_TREE_PREEMPT_RCU=y.
> 
> Add a rcu_read_lock/unlock() section around the code which accesses
> __task_cred().
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Acked-by: David Howells <dhowells@redhat.com>