From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752154AbcHKK4i (ORCPT ); Thu, 11 Aug 2016 06:56:38 -0400 Received: from ec2-52-27-115-49.us-west-2.compute.amazonaws.com ([52.27.115.49]:41706 "EHLO s-opensource.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751543AbcHKK4h (ORCPT ); Thu, 11 Aug 2016 06:56:37 -0400 Message-ID: <57AC59D0.7030408@osg.samsung.com> Date: Thu, 11 Aug 2016 11:56:16 +0100 From: Luis de Bethencourt User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.8.0 MIME-Version: 1.0 To: Salah Triki , akpm@linux-foundation.org, viro@zeniv.linux.org.uk CC: linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/4] befs: check allocation_group number before use References: <8f7f9b76ead677bdc834867e549ea6c4d1c04ccd.1470867071.git.salah.triki@gmail.com> In-Reply-To: <8f7f9b76ead677bdc834867e549ea6c4d1c04ccd.1470867071.git.salah.triki@gmail.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/08/16 23:12, Salah Triki wrote: > Check that the allocation group number is not greater or equal to the > number of allocations group in the file system and return BEF_ERR in the > case of error. > > Signed-off-by: Salah Triki > --- > fs/befs/befs.h | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/fs/befs/befs.h b/fs/befs/befs.h > index 55f3ea2..6daf4c4 100644 > --- a/fs/befs/befs.h > +++ b/fs/befs/befs.h > @@ -121,6 +121,11 @@ BEFS_I(const struct inode *inode) > static inline befs_blocknr_t > iaddr2blockno(struct super_block *sb, const befs_inode_addr *iaddr) > { > + if (iaddr->allocation_group >= BEFS_SB(sb)->num_ags) { > + befs_error(sb, "BEFS: Invalid allocation group %u, max is %u", > + iaddr->allocation_group, BEFS_SB(sb)->num_ags); > + return BEFS_ERR; > + } > return ((iaddr->allocation_group << BEFS_SB(sb)->ag_shift) + > iaddr->start); > } > Hi Salah, To understand why would we check for this. When can this error happen? I mean, when can iaddr2blockno() be called with an out of bounds allocation group? Thanks, Luis