From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id 129927F37 for ; Mon, 26 Aug 2013 11:51:24 -0500 (CDT) Date: Mon, 26 Aug 2013 11:51:23 -0500 From: Ben Myers Subject: Re: [PATCH] xfsprogs: fix Out-of-bounds access in repair/dinode.c Message-ID: <20130826165123.GW7153@sgi.com> References: <1376287861.2822.13.camel@ThinkPad-T5421> <5214EFFF.4060105@sgi.com> <20130823163828.GS5262@sgi.com> <1377483327.2834.7.camel@ThinkPad-T5421> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1377483327.2834.7.camel@ThinkPad-T5421> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Li Zhong Cc: Rich Johnston , Chandra Seetharaman , xfsprogs Hey Zhong, On Mon, Aug 26, 2013 at 10:15:27AM +0800, Li Zhong wrote: > On Fri, 2013-08-23 at 11:38 -0500, Ben Myers wrote: > > Hey Rich and Li Zhong, > > > > On Wed, Aug 21, 2013 at 11:51:11AM -0500, Rich Johnston wrote: > > > Looks good, thanks for the patch Li Zhong. it has been committed. > > > > > > --Rich > > > > > > Reviewed-by: Rich Johnston > > > > > > commit e7c05095f5baa9cd2e35a6de03d7dd9f51dd3910 > > > Author: Li Zhong > > > Date: Mon Aug 12 06:11:01 2013 +0000 > > > > > > xfsprogs: fix Out-of-bounds access in repair/dinode.c > > > > > > On 08/12/2013 01:11 AM, Li Zhong wrote: > > > >Following is reported by coverity in bug 1061528: > > > > > > > >187 __dirty_no_modify_ret(dirty); > > > > > > > >CID 1061528 (#1 of 1): Out-of-bounds access (OVERRUN)53. overrun-buffer-arg: Overrunning array "dinoc->di_pad" of 6 bytes by passing it to a function which accesses it at byte offset 15 using argument "16UL". > > > >188 memset(dinoc->di_pad, 0, 16); > > > > > > > >It seems that di_pad here should be di_pad2, as sekharan pointed out. > > > > > > > >Signed-off-by: Li Zhong > > > >--- > > > > repair/dinode.c | 4 ++-- > > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > > >diff --git a/repair/dinode.c b/repair/dinode.c > > > >index e607f0b..94bf2f8 100644 > > > >--- a/repair/dinode.c > > > >+++ b/repair/dinode.c > > > >@@ -183,9 +183,9 @@ clear_dinode_core(struct xfs_mount *mp, xfs_dinode_t *dinoc, xfs_ino_t ino_num) > > > > } > > > > > > > > for (i = 0; i < 16; i++) { > > > >- if (dinoc->di_pad[i] != 0) { > > > >+ if (dinoc->di_pad2[i] != 0) { > > > > __dirty_no_modify_ret(dirty); > > > >- memset(dinoc->di_pad, 0, 16); > > > >+ memset(dinoc->di_pad2, 0, 16); > > > > break; > > > > } > > > > } > > > > We also discussed this issue a bit in this thread: > > http://oss.sgi.com/archives/xfs/2013-08/msg00228.html > > > > Looks like the loop itself is incorrect and should be removed, and Eric has > > suggested that the conditional be changed to a memcmp in case the size of the > > pad changes in the future. Would either of you care to spin up another patch > > to clean it up? > > Hi Ben, > > If I understand correctly, we need to change 16 to be a sizeof the > di_pad2 array(like the fix attached below)? > > It seems to me that the loop is needed to check all of the 16 entries in > the array? You are correct. We need the loop... > Thanks, Zhong > > --- > diff --git a/repair/dinode.c b/repair/dinode.c > index b2b9a95..7469fc8 100644 > --- a/repair/dinode.c > +++ b/repair/dinode.c > @@ -182,10 +182,10 @@ clear_dinode_core(struct xfs_mount *mp, xfs_dinode_t *dinoc, xfs_ino_t ino_num) > platform_uuid_copy(&dinoc->di_uuid, &mp->m_sb.sb_uuid); > } > > - for (i = 0; i < 16; i++) { > + for (i = 0; i < sizeof(dinoc->di_pad2)/sizeof(dinoc->di_pad2[0]); i++) { Just sizeof(dinoc->di_pad2) would be enough here, right? No need for the division I think. > if (dinoc->di_pad2[i] != 0) { > __dirty_no_modify_ret(dirty); > - memset(dinoc->di_pad2, 0, 16); > + memset(dinoc->di_pad2, 0, sizeof(dinoc->di_pad2)); ^^^^^^^^^^^^^^^^^^^^^^ That guy will return 16, so we'll memset off the end of di_pad2. sizeof(dinoc->di_pad2[0]) would work. Thanks! -Ben _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs