From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:42524 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751196AbdGYLBW (ORCPT ); Tue, 25 Jul 2017 07:01:22 -0400 Date: Tue, 25 Jul 2017 07:01:21 -0400 From: Brian Foster Subject: Re: [PATCH] xfs: check that dir block entries don't off the end of the buffer Message-ID: <20170725110121.GC16188@bfoster.bfoster> References: <20170721220122.GW4224@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170721220122.GW4224@magnolia> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: "Darrick J. Wong" Cc: xfs On Fri, Jul 21, 2017 at 03:01:22PM -0700, Darrick J. Wong wrote: > When we're checking the entries in a directory buffer, make sure that > the entry length doesn't push us off the end of the buffer. Found via > xfs/388 writing ones to the freetag length field and xfs_repair crashing. > > Signed-off-by: Darrick J. Wong > --- > fs/xfs/libxfs/xfs_dir2_data.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/fs/xfs/libxfs/xfs_dir2_data.c b/fs/xfs/libxfs/xfs_dir2_data.c > index d478065..8727a43 100644 > --- a/fs/xfs/libxfs/xfs_dir2_data.c > +++ b/fs/xfs/libxfs/xfs_dir2_data.c > @@ -136,6 +136,8 @@ __xfs_dir3_data_check( > */ > if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) { > XFS_WANT_CORRUPTED_RETURN(mp, lastfree == 0); > + XFS_WANT_CORRUPTED_RETURN(mp, endp >= > + p + be16_to_cpu(dup->length)); FWIW, the rest of the code seems to use the dup/dep pointers for verification and explicitly casts to char * where necessary. I don't see that it really matters, so: Reviewed-by: Brian Foster > XFS_WANT_CORRUPTED_RETURN(mp, > be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)) == > (char *)dup - (char *)hdr); > @@ -164,6 +166,8 @@ __xfs_dir3_data_check( > XFS_WANT_CORRUPTED_RETURN(mp, dep->namelen != 0); > XFS_WANT_CORRUPTED_RETURN(mp, > !xfs_dir_ino_validate(mp, be64_to_cpu(dep->inumber))); > + XFS_WANT_CORRUPTED_RETURN(mp, endp >= > + p + ops->data_entsize(dep->namelen)); > XFS_WANT_CORRUPTED_RETURN(mp, > be16_to_cpu(*ops->data_entry_tag_p(dep)) == > (char *)dep - (char *)hdr); > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html