From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757788Ab0DWPw2 (ORCPT ); Fri, 23 Apr 2010 11:52:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:23065 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757750Ab0DWPwZ (ORCPT ); Fri, 23 Apr 2010 11:52:25 -0400 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <20100424002319.d68a3819.toshi.okajima@jp.fujitsu.com> References: <20100424002319.d68a3819.toshi.okajima@jp.fujitsu.com> <20100423195127.48095127.toshi.okajima@jp.fujitsu.com> <20100422163755.355794e3.toshi.okajima@jp.fujitsu.com> <7894.1271931370@redhat.com> <20100423194547.3135efb8.toshi.okajima@jp.fujitsu.com> <10934.1272022437@redhat.com> To: Toshiyuki Okajima Cc: dhowells@redhat.com, keyrings@linux-nfs.org, security@kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/1][BUG][TAKE2] KEYRINGS: find_keyring_by_name() can gain the freed keyring Date: Fri, 23 Apr 2010 16:52:16 +0100 Message-ID: <1790.1272037936@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Toshiyuki Okajima wrote: > > Better still, atomic_inc_not_zero(). How about the attached patch? > Your fix looks good to me. But, if usage count of the keyring is 0, > I think it better to return -ENOKEY immediately. The problem with that is that someone else may have created a keyring with the same name that you can't then reach until the dead keyring is deleted. David