On Fri, Jun 17, 2022 at 01:06:41PM +0300, Amir Goldstein wrote: > From: "Darrick J. Wong" <djwong@xxxxxxxxxx> > > commit e014f37db1a2d109afa750042ac4d69cf3e3d88e upstream. > > [remove userns argument of setattr_copy() for backport] > > Filipe Manana pointed out that XFS' behavior w.r.t. setuid/setgid > revocation isn't consistent with btrfs[1] or ext4. Those two > filesystems use the VFS function setattr_copy to convey certain > attributes from struct iattr into the VFS inode structure. > > Andrey Zhadchenko reported[2] that XFS uses the wrong user namespace to > decide if it should clear setgid and setuid on a file attribute update. > This is a second symptom of the problem that Filipe noticed. > > XFS, on the other hand, open-codes setattr_copy in xfs_setattr_mode, > xfs_setattr_nonsize, and xfs_setattr_time. Regrettably, setattr_copy is > /not/ a simple copy function; it contains additional logic to clear the > setgid bit when setting the mode, and XFS' version no longer matches. > > The VFS implements its own setuid/setgid stripping logic, which > establishes consistent behavior. It's a tad unfortunate that it's > scattered across notify_change, should_remove_suid, and setattr_copy but > XFS should really follow the Linux VFS. Adapt XFS to use the VFS > functions and get rid of the old functions. > > [1] https://lore.kernel.org/fstests/CAL3q7H47iNQ=Wmk83WcGB-KBJVOEtR9+qGczzCeXJ9Y2KCV25Q@xxxxxxxxxxxxxx/ > [2] https://lore.kernel.org/linux-xfs/20220221182218.748084-1-andrey.zhadchenko@xxxxxxxxxxxxx/ > > Fixes: 7fa294c8991c ("userns: Allow chown and setgid preservation") > Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx> > Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx> > Reviewed-by: Christoph Hellwig <hch@xxxxxx> > Reviewed-by: Christian Brauner <brauner@xxxxxxxxxx> > Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx> Same question as I posted to Leah's series -- have all the necessary VFS fixes and whatnot been backported to 5.10? Such that all the new sgid inheritance tests actually pass with this patch applied? :) --D > --- > fs/xfs/xfs_iops.c | 56 +++-------------------------------------------- > fs/xfs/xfs_pnfs.c | 3 ++- > 2 files changed, 5 insertions(+), 54 deletions(-) > > diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c > index b7f7b31a77d5..5711c8c12625 100644 > --- a/fs/xfs/xfs_iops.c > +++ b/fs/xfs/xfs_iops.c > @@ -595,37 +595,6 @@ xfs_vn_getattr( > return 0; > } > > -static void > -xfs_setattr_mode( > - struct xfs_inode *ip, > - struct iattr *iattr) > -{ > - struct inode *inode = VFS_I(ip); > - umode_t mode = iattr->ia_mode; > - > - ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL)); > - > - inode->i_mode &= S_IFMT; > - inode->i_mode |= mode & ~S_IFMT; > -} > - > -void > -xfs_setattr_time( > - struct xfs_inode *ip, > - struct iattr *iattr) > -{ > - struct inode *inode = VFS_I(ip); > - > - ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL)); > - > - if (iattr->ia_valid & ATTR_ATIME) > - inode->i_atime = iattr->ia_atime; > - if (iattr->ia_valid & ATTR_CTIME) > - inode->i_ctime = iattr->ia_ctime; > - if (iattr->ia_valid & ATTR_MTIME) > - inode->i_mtime = iattr->ia_mtime; > -} > - > static int > xfs_vn_change_ok( > struct dentry *dentry, > @@ -740,16 +709,6 @@ xfs_setattr_nonsize( > goto out_cancel; > } > > - /* > - * CAP_FSETID overrides the following restrictions: > - * > - * The set-user-ID and set-group-ID bits of a file will be > - * cleared upon successful return from chown() > - */ > - if ((inode->i_mode & (S_ISUID|S_ISGID)) && > - !capable(CAP_FSETID)) > - inode->i_mode &= ~(S_ISUID|S_ISGID); > - > /* > * Change the ownerships and register quota modifications > * in the transaction. > @@ -761,7 +720,6 @@ xfs_setattr_nonsize( > olddquot1 = xfs_qm_vop_chown(tp, ip, > &ip->i_udquot, udqp); > } > - inode->i_uid = uid; > } > if (!gid_eq(igid, gid)) { > if (XFS_IS_QUOTA_RUNNING(mp) && XFS_IS_GQUOTA_ON(mp)) { > @@ -772,15 +730,10 @@ xfs_setattr_nonsize( > olddquot2 = xfs_qm_vop_chown(tp, ip, > &ip->i_gdquot, gdqp); > } > - inode->i_gid = gid; > } > } > > - if (mask & ATTR_MODE) > - xfs_setattr_mode(ip, iattr); > - if (mask & (ATTR_ATIME|ATTR_CTIME|ATTR_MTIME)) > - xfs_setattr_time(ip, iattr); > - > + setattr_copy(inode, iattr); > xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); > > XFS_STATS_INC(mp, xs_ig_attrchg); > @@ -1025,11 +978,8 @@ xfs_setattr_size( > xfs_inode_clear_eofblocks_tag(ip); > } > > - if (iattr->ia_valid & ATTR_MODE) > - xfs_setattr_mode(ip, iattr); > - if (iattr->ia_valid & (ATTR_ATIME|ATTR_CTIME|ATTR_MTIME)) > - xfs_setattr_time(ip, iattr); > - > + ASSERT(!(iattr->ia_valid & (ATTR_UID | ATTR_GID))); > + setattr_copy(inode, iattr); > xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); > > XFS_STATS_INC(mp, xs_ig_attrchg); > diff --git a/fs/xfs/xfs_pnfs.c b/fs/xfs/xfs_pnfs.c > index f3082a957d5e..ae61094bc9d1 100644 > --- a/fs/xfs/xfs_pnfs.c > +++ b/fs/xfs/xfs_pnfs.c > @@ -283,7 +283,8 @@ xfs_fs_commit_blocks( > xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL); > xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); > > - xfs_setattr_time(ip, iattr); > + ASSERT(!(iattr->ia_valid & (ATTR_UID | ATTR_GID))); > + setattr_copy(inode, iattr); > if (update_isize) { > i_size_write(inode, iattr->ia_size); > ip->i_d.di_size = iattr->ia_size; > -- > 2.25.1 >
