Commit 42c49d7f authored Jun 21, 2013 by Carlos Maiolino Committed by Ben Myers Jul 10, 2013

xfs: fix sgid inheritance for subdirectories inheriting default acls [V3]



XFS removes sgid bits of subdirectories under a directory containing a default
acl.

When a default acl is set, it implies xfs to call xfs_setattr_nonsize() in its
code path. Such function is shared among mkdir and chmod system calls, and
does some checks unneeded by mkdir (calling inode_change_ok()). Such checks
remove sgid bit from the inode after it has been granted.

With this patch, we extend the meaning of XFS_ATTR_NOACL flag to avoid these
checks when acls are being inherited (thanks hch).

Also, xfs_setattr_mode, doesn't need to re-check for group id and capabilities
permissions, this only implies in another try to remove sgid bit from the
directories. Such check is already done either on inode_change_ok() or
xfs_setattr_nonsize().

Changelog:

V2: Extends the meaning of XFS_ATTR_NOACL instead of wrap the tests into another
    function

V3: Remove S_ISDIR check in xfs_setattr_nonsize() from the patch

Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

parent b0a9dab7

fs/xfs/xfs_iops.c

+10 −10

Original line number	Diff line number	Diff line
		@@ -467,9 +467,6 @@ xfs_setattr_mode(
		ASSERT(tp);
		ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));

		if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
		mode &= ~S_ISGID;

		ip->i_d.di_mode &= S_IFMT;
		ip->i_d.di_mode \|= mode & ~S_IFMT;

		@@ -495,6 +492,8 @@ xfs_setattr_nonsize(

		trace_xfs_setattr(ip);

		/* If acls are being inherited, we already have this checked */
		if (!(flags & XFS_ATTR_NOACL)) {
		if (mp->m_flags & XFS_MOUNT_RDONLY)
		return XFS_ERROR(EROFS);

		@@ -504,6 +503,7 @@ xfs_setattr_nonsize(
		error = -inode_change_ok(inode, iattr);
		if (error)
		return XFS_ERROR(error);
		}

		ASSERT((mask & ATTR_SIZE) == 0);