From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp2120.oracle.com ([156.151.31.85]:48946 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727478AbeGaBQF (ORCPT ); Mon, 30 Jul 2018 21:16:05 -0400 Date: Mon, 30 Jul 2018 16:38:35 -0700 From: "Darrick J. Wong" Subject: Re: [PATCH 2/3] libxfs: add more bounds checking to sb sanity checks Message-ID: <20180730233835.GR30972@magnolia> References: <153292860880.19274.14533449137039985963.stgit@magnolia> <153292862122.19274.13281750487162777731.stgit@magnolia> <82b9a6d9-c5b9-112d-98eb-c9e7153e67da@sandeen.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <82b9a6d9-c5b9-112d-98eb-c9e7153e67da@sandeen.net> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Eric Sandeen Cc: linux-xfs@vger.kernel.org, Bill O'Donnell On Mon, Jul 30, 2018 at 06:16:40PM -0500, Eric Sandeen wrote: > On 7/30/18 12:30 AM, Darrick J. Wong wrote: > > From: Bill O'Donnell > > > > Current sb verifier doesn't check bounds on sb_fdblocks and sb_ifree. > > Add sanity checks for these parameters. > > > > Signed-off-by: Bill O'Donnell > > [darrick: port to refactored sb validation predicates] > > Signed-off-by: Darrick J. Wong > > comment nitpicks below, but otherwise > > Reviewed-by: Eric Sandeen > > > --- > > fs/xfs/libxfs/xfs_sb.c | 12 ++++++++++++ > > 1 file changed, 12 insertions(+) > > > > > > diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c > > index 516bef7b0f50..64bc471d57e6 100644 > > --- a/fs/xfs/libxfs/xfs_sb.c > > +++ b/fs/xfs/libxfs/xfs_sb.c > > @@ -153,6 +153,18 @@ xfs_validate_sb_write( > > struct xfs_mount *mp, > > struct xfs_sb *sbp) > > { > > + /* > > + * Carry out additional sb sanity checks exclusively for writes. > > We're in xfs_validate_sb_write so that's obvious, can drop this line. > > > + * We don't do these checks for reads, since faulty parameters could > > + * be fixed in the log, and we shouldn't prohibit mounting for those > > + * cases. > > + */ > > Hm, it's not really a log reaplay issue, right? These summary counters > get reinitialized at mount, so failing to mount before we overwrite them > anyway makes no sense. Well, we don't reinitialize them if ( (!lazysbcount) or (clean log) ) and (non-crazy values)... > /* > * These summary counters get re-initialized after they are read > * during mount, so this is a write-only check. They're not always re-initialized -- only if we had a dirty lazysbcont fs or the values were crazy. /* * Carry out additional sb summary counter sanity checks when we write * the superblock. We skip this in the read validator because there * could be newer superblocks in the log and if the values are garbage * even after replay we'll recalculate them at the end of log mount. */ --D > */ > > ? And yeah, modulo lazycount... but whatevs. > > -Eric > > > + if (sbp->sb_fdblocks > sbp->sb_dblocks || > > + sbp->sb_ifree > sbp->sb_icount) { > > + xfs_warn(mp, "SB summary counter sanity check failed"); > > + return -EFSCORRUPTED; > > + } > > + > > if (!xfs_sb_version_hascrc(sbp)) > > return 0; > -- > 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