From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx3-rdu2.redhat.com ([66.187.233.73]:44276 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730292AbeGZTnb (ORCPT ); Thu, 26 Jul 2018 15:43:31 -0400 Date: Thu, 26 Jul 2018 13:25:29 -0500 From: Bill O'Donnell Subject: Re: [PATCH 1/2] libxfs: add more bounds checking to sb sanity checks Message-ID: <20180726182529.GB20780@redhat.com> References: <153262651940.8934.17525988748289196893.stgit@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <153262651940.8934.17525988748289196893.stgit@magnolia> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org On Thu, Jul 26, 2018 at 10:35:19AM -0700, 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: remove the icount check, tweak the comments a little] > Reviewed-by: Darrick J. Wong > Signed-off-by: Darrick J. Wong > --- Reviewed-by: Bill O'Donnell > fs/xfs/libxfs/xfs_sb.c | 45 +++++++++++++++++++++++++++++++++++---------- > 1 file changed, 35 insertions(+), 10 deletions(-) > > > diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c > index b3ad15956366..b2c683588519 100644 > --- a/fs/xfs/libxfs/xfs_sb.c > +++ b/fs/xfs/libxfs/xfs_sb.c > @@ -599,22 +599,16 @@ xfs_sb_to_disk( > static int > xfs_sb_verify( > struct xfs_buf *bp, > + struct xfs_sb *sb, > bool check_version) > { > struct xfs_mount *mp = bp->b_target->bt_mount; > - struct xfs_sb sb; > - > - /* > - * Use call variant which doesn't convert quota flags from disk > - * format, because xfs_mount_validate_sb checks the on-disk flags. > - */ > - __xfs_sb_from_disk(&sb, XFS_BUF_TO_SBP(bp), false); > > /* > * Only check the in progress field for the primary superblock as > * mkfs.xfs doesn't clear it from secondary superblocks. > */ > - return xfs_mount_validate_sb(mp, &sb, > + return xfs_mount_validate_sb(mp, sb, > bp->b_maps[0].bm_bn == XFS_SB_DADDR, > check_version); > } > @@ -637,6 +631,7 @@ xfs_sb_read_verify( > { > struct xfs_mount *mp = bp->b_target->bt_mount; > struct xfs_dsb *dsb = XFS_BUF_TO_SBP(bp); > + struct xfs_sb sb; > int error; > > /* > @@ -657,7 +652,13 @@ xfs_sb_read_verify( > } > } > } > - error = xfs_sb_verify(bp, true); > + > + /* > + * Use call variant which doesn't convert quota flags from disk > + * format, because xfs_mount_validate_sb checks the on-disk flags. > + */ > + __xfs_sb_from_disk(&sb, XFS_BUF_TO_SBP(bp), false); > + error = xfs_sb_verify(bp, &sb, true); > > out_error: > if (error == -EFSCORRUPTED || error == -EFSBADCRC) > @@ -693,9 +694,33 @@ xfs_sb_write_verify( > { > struct xfs_mount *mp = bp->b_target->bt_mount; > struct xfs_buf_log_item *bip = bp->b_log_item; > + struct xfs_sb sb; > int error; > > - error = xfs_sb_verify(bp, false); > + /* > + * Use call variant which doesn't convert quota flags from disk > + * format, because xfs_mount_validate_sb checks the on-disk flags. > + */ > + __xfs_sb_from_disk(&sb, XFS_BUF_TO_SBP(bp), false); > + > + error = xfs_sb_verify(bp, &sb, false); > + if (error) > + goto err; > + > + /* > + * Carry out additional sb sanity checks exclusively for writes. > + * 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. > + */ > + if (sb.sb_fdblocks > sb.sb_dblocks || > + sb.sb_ifree > sb.sb_icount) { > + xfs_notice(mp, "SB summary counter sanity check failed"); > + error = -EFSCORRUPTED; > + goto err; > + } > + > +err: > if (error) { > xfs_verifier_error(bp, error, __this_address); > return; >