From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp2120.oracle.com ([156.151.31.85]:33776 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966349AbeF1N4T (ORCPT ); Thu, 28 Jun 2018 09:56:19 -0400 Date: Thu, 28 Jun 2018 06:56:05 -0700 From: "Darrick J. Wong" Subject: Re: [PATCH V2] xfs: Initialize variables in xfs_alloc_get_rec before using them Message-ID: <20180628135605.GG5711@magnolia> References: <20180628092835.25879-1-cmaiolino@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180628092835.25879-1-cmaiolino@redhat.com> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Carlos Maiolino Cc: linux-xfs@vger.kernel.org On Thu, Jun 28, 2018 at 11:28:35AM +0200, Carlos Maiolino wrote: > Make sure we initialize *bno and *len, before jumping to out_bad_rec > label, and risk calling xfs_warn() with uninitialized variables. > > Coverity: 100898 > Coverity: 1437081 > Coverity: 1437129 > Coverity: 1437191 > Coverity: 1437201 > Coverity: 1437212 > Coverity: 1437341 > Signed-off-by: Carlos Maiolino Looks ok, Reviewed-by: Darrick J. Wong --D > --- > > This is based on Darrick's suggestion, although, I believe initializing *bno and > *len before testing if *len is empty or not is a bit more clear than changing > xfs_warn() to use rec->alloc.ar_startblock and rec->alloc.ar_blockcount > directly. > > fs/xfs/libxfs/xfs_alloc.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c > index eef466260d43..75dbdc14c45f 100644 > --- a/fs/xfs/libxfs/xfs_alloc.c > +++ b/fs/xfs/libxfs/xfs_alloc.c > @@ -223,12 +223,13 @@ xfs_alloc_get_rec( > error = xfs_btree_get_rec(cur, &rec, stat); > if (error || !(*stat)) > return error; > - if (rec->alloc.ar_blockcount == 0) > - goto out_bad_rec; > > *bno = be32_to_cpu(rec->alloc.ar_startblock); > *len = be32_to_cpu(rec->alloc.ar_blockcount); > > + if (*len == 0) > + goto out_bad_rec; > + > /* check for valid extent range, including overflow */ > if (!xfs_verify_agbno(mp, agno, *bno)) > goto out_bad_rec; > -- > 2.14.3 > > -- > 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