From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752633AbYLPF6T (ORCPT ); Tue, 16 Dec 2008 00:58:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751060AbYLPF6J (ORCPT ); Tue, 16 Dec 2008 00:58:09 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:51039 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750815AbYLPF6I (ORCPT ); Tue, 16 Dec 2008 00:58:08 -0500 Date: Mon, 15 Dec 2008 21:57:06 -0800 From: Andrew Morton To: Cyrill Gorcunov Cc: Alexander Viro , LKML Subject: Re: [PATCH] fs - fix name overwrite in __register_chrdev_region Message-Id: <20081215215706.7707315c.akpm@linux-foundation.org> In-Reply-To: <20081213214911.GI16354@localhost> References: <20081213214911.GI16354@localhost> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.5; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 14 Dec 2008 00:49:11 +0300 Cyrill Gorcunov wrote: > It's possible to register chdev with a name size > exactly the same as was allocated in structure. > It seems it was not intedned behaviour. > > At least chrdev_show does not like it. > > Signed-off-by: Cyrill Gorcunov > --- > > fs/char_dev.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > Index: linux-2.6.git/fs/char_dev.c > =================================================================== > --- linux-2.6.git.orig/fs/char_dev.c > +++ linux-2.6.git/fs/char_dev.c > @@ -120,7 +120,7 @@ __register_chrdev_region(unsigned int ma > cd->major = major; > cd->baseminor = baseminor; > cd->minorct = minorct; > - strncpy(cd->name,name, 64); > + strncpy(cd->name, name, sizeof(cd->name) - 1); > > i = major_to_index(major); > OK. strlcpy() prodces a more pleasing result: --- a/fs/char_dev.c~fs-fix-name-overwrite-in-__register_chrdev_region +++ a/fs/char_dev.c @@ -120,7 +120,7 @@ __register_chrdev_region(unsigned int ma cd->major = major; cd->baseminor = baseminor; cd->minorct = minorct; - strncpy(cd->name,name, 64); + strlcpy(cd->name, name, sizeof(cd->name)); i = major_to_index(major); _