From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: [PATCH 1/2] kernfs_path_from_node_locked: don't overwrite nlen Date: Mon, 2 May 2016 09:41:17 -0700 Message-ID: <20160502164117.GA32449@kroah.com> References: <1460923472-29370-1-git-send-email-serge.hallyn@ubuntu.com> <1460923472-29370-2-git-send-email-serge.hallyn@ubuntu.com> <20160420194313.GA4775@htj.duckdns.org> <20160502163256.GT7822@mtj.duckdns.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20160502163256.GT7822-qYNAdHglDFBN0TnZuCh8vA@public.gmane.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Tejun Heo Cc: linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, serge.hallyn-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org, hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org On Mon, May 02, 2016 at 12:32:56PM -0400, Tejun Heo wrote: > On Wed, Apr 20, 2016 at 03:43:13PM -0400, Tejun Heo wrote: > > On Sun, Apr 17, 2016 at 03:04:31PM -0500, serge.hallyn-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org wrote: > > > From: Serge Hallyn > > > > > > We've calculated @len to be the bytes we need for '/..' entries from > > > @kn_from to the common ancestor, and calculated @nlen to be the extra > > > bytes we need to get from the common ancestor to @kn_to. We use them > > > as such at the end. But in the loop copying the actual entries, we > > > overwrite @nlen. Use a temporary variable for that instead. > > > > > > Without this, the return length, when the buffer is large enough, is > > > wrong. (When the buffer is NULL or too small, the returned value is > > > correct. The buffer contents are also correct.) > > > > > > Interestingly, no callers of this function are affected by this as of > > > yet. However the upcoming cgroup_show_path() will be. > > > > > > Signed-off-by: Serge Hallyn > > > > Acked-by: Tejun Heo > > > > Greg, can you please pick this one up for v4.6? > > Looks like Greg missed this one. Greg, I'll route this through > cgroup/for-4.6-fixes. Please do, sorry, it's not in my queue anymore :( From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754453AbcEBQlU (ORCPT ); Mon, 2 May 2016 12:41:20 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:49311 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750836AbcEBQlS (ORCPT ); Mon, 2 May 2016 12:41:18 -0400 Date: Mon, 2 May 2016 09:41:17 -0700 From: Greg KH To: Tejun Heo Cc: linux-kernel@vger.kernel.org, adityakali@google.com, linux-api@vger.kernel.org, containers@lists.linux-foundation.org, cgroups@vger.kernel.org, akpm@linux-foundation.org, ebiederm@xmission.com, serge.hallyn@ubuntu.com, lizefan@huawei.com, hannes@cmpxchg.org Subject: Re: [PATCH 1/2] kernfs_path_from_node_locked: don't overwrite nlen Message-ID: <20160502164117.GA32449@kroah.com> References: <1460923472-29370-1-git-send-email-serge.hallyn@ubuntu.com> <1460923472-29370-2-git-send-email-serge.hallyn@ubuntu.com> <20160420194313.GA4775@htj.duckdns.org> <20160502163256.GT7822@mtj.duckdns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160502163256.GT7822@mtj.duckdns.org> User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 02, 2016 at 12:32:56PM -0400, Tejun Heo wrote: > On Wed, Apr 20, 2016 at 03:43:13PM -0400, Tejun Heo wrote: > > On Sun, Apr 17, 2016 at 03:04:31PM -0500, serge.hallyn@ubuntu.com wrote: > > > From: Serge Hallyn > > > > > > We've calculated @len to be the bytes we need for '/..' entries from > > > @kn_from to the common ancestor, and calculated @nlen to be the extra > > > bytes we need to get from the common ancestor to @kn_to. We use them > > > as such at the end. But in the loop copying the actual entries, we > > > overwrite @nlen. Use a temporary variable for that instead. > > > > > > Without this, the return length, when the buffer is large enough, is > > > wrong. (When the buffer is NULL or too small, the returned value is > > > correct. The buffer contents are also correct.) > > > > > > Interestingly, no callers of this function are affected by this as of > > > yet. However the upcoming cgroup_show_path() will be. > > > > > > Signed-off-by: Serge Hallyn > > > > Acked-by: Tejun Heo > > > > Greg, can you please pick this one up for v4.6? > > Looks like Greg missed this one. Greg, I'll route this through > cgroup/for-4.6-fixes. Please do, sorry, it's not in my queue anymore :(