Ocfs2 devel - Jun 2017 - [PATCH 0/11 v1] Fix inheritance of SGID in presence of default ACLs

Hello,

this patch set fixes a problem introduced by commit 073931017b49
"posix_acl:
Clear SGID bit when setting file permissions". The problem is that when new
directory 'DIR1' is created in a directory 'DIR0' with SGID bit
set, DIR1 is
expected to have SGID bit set (and owning group equal to the owning group of
'DIR0'). However when 'DIR0' also has some default ACLs that
'DIR1' inherits,
setting these ACLs will result in SGID bit on 'DIR1' to get cleared if
user is
not member of the owning group.

The problem is fixed by moving posix_acl_update_mode() so that it does not
get called when default ACLs are inherited.

I have created new generic/441 test for this and verified that generic/314,
generic/375, and generic/441 pass for ext2, ext4, btrfs, xfs, ocfs2, reiserfs.

All patches in this series are completely independent so fs maintainers please
pick them up as soon as they get reviewed. I'm leaving for three weeks of
vacation at the end of the week so I won't be able to push this further for
some time.

								Honza

The function is never called outside of fs/ocfs2/acl.c.

CC: Joel Becker <jlbec at evilplan.org>
CC: ocfs2-devel at oss.oracle.com
Signed-off-by: Jan Kara <jack at suse.cz>
---
 fs/ocfs2/acl.c | 2 +-
 fs/ocfs2/acl.h | 7 -------
 2 files changed, 1 insertion(+), 8 deletions(-)

diff --git a/fs/ocfs2/acl.c b/fs/ocfs2/acl.c
index dc22ba8c710f..3b9c3638a381 100644
--- a/fs/ocfs2/acl.c
+++ b/fs/ocfs2/acl.c
@@ -221,7 +221,7 @@ static int ocfs2_acl_set_mode(struct inode *inode, struct
buffer_head *di_bh,
 /*
  * Set the access or default ACL of an inode.
  */
-int ocfs2_set_acl(handle_t *handle,
+static int ocfs2_set_acl(handle_t *handle,
 			 struct inode *inode,
 			 struct buffer_head *di_bh,
 			 int type,
diff --git a/fs/ocfs2/acl.h b/fs/ocfs2/acl.h
index 2783a75b3999..7be0bb756286 100644
--- a/fs/ocfs2/acl.h
+++ b/fs/ocfs2/acl.h
@@ -28,13 +28,6 @@ struct ocfs2_acl_entry {
 
 struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type);
 int ocfs2_iop_set_acl(struct inode *inode, struct posix_acl *acl, int type);
-int ocfs2_set_acl(handle_t *handle,
-			 struct inode *inode,
-			 struct buffer_head *di_bh,
-			 int type,
-			 struct posix_acl *acl,
-			 struct ocfs2_alloc_context *meta_ac,
-			 struct ocfs2_alloc_context *data_ac);
 extern int ocfs2_acl_chmod(struct inode *, struct buffer_head *);
 extern int ocfs2_init_acl(handle_t *, struct inode *, struct inode *,
 			  struct buffer_head *, struct buffer_head *,
-- 
2.12.3

When new directory 'DIR1' is created in a directory 'DIR0' with
SGID bit
set, DIR1 is expected to have SGID bit set (and owning group equal to
the owning group of 'DIR0'). However when 'DIR0' also has some
default
ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on
'DIR1' to get cleared if user is not member of the owning group.

Fix the problem by moving posix_acl_update_mode() out of ocfs2_set_acl()
into ocfs2_iop_set_acl(). That way the function will not be called when
inheriting ACLs which is what we want as it prevents SGID bit clearing
and the mode has been properly set by posix_acl_create() anyway. Also
posix_acl_chmod() that is calling ocfs2_set_acl() takes care of updating
mode itself.

Fixes: 073931017b49d9458aa351605b43a7e34598caef
CC: stable at vger.kernel.org
CC: Joel Becker <jlbec at evilplan.org>
CC: ocfs2-devel at oss.oracle.com
Signed-off-by: Jan Kara <jack at suse.cz>
---
 fs/ocfs2/acl.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/fs/ocfs2/acl.c b/fs/ocfs2/acl.c
index 3b9c3638a381..40b5cc97f7b0 100644
--- a/fs/ocfs2/acl.c
+++ b/fs/ocfs2/acl.c
@@ -240,18 +240,6 @@ static int ocfs2_set_acl(handle_t *handle,
 	switch (type) {
 	case ACL_TYPE_ACCESS:
 		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
-		if (acl) {
-			umode_t mode;
-
-			ret = posix_acl_update_mode(inode, &mode, &acl);
-			if (ret)
-				return ret;
-
-			ret = ocfs2_acl_set_mode(inode, di_bh,
-						 handle, mode);
-			if (ret)
-				return ret;
-		}
 		break;
 	case ACL_TYPE_DEFAULT:
 		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
@@ -289,7 +277,19 @@ int ocfs2_iop_set_acl(struct inode *inode, struct posix_acl
*acl, int type)
 	had_lock = ocfs2_inode_lock_tracker(inode, &bh, 1, &oh);
 	if (had_lock < 0)
 		return had_lock;
+	if (type == ACL_TYPE_ACCESS && acl) {
+		umode_t mode;
+
+		status = posix_acl_update_mode(inode, &mode, &acl);
+		if (status)
+			goto unlock;
+
+		status = ocfs2_acl_set_mode(inode, bh, NULL, mode);
+		if (status)
+			goto unlock;
+	}
 	status = ocfs2_set_acl(NULL, inode, bh, type, acl, NULL, NULL);
+unlock:
 	ocfs2_inode_unlock_tracker(inode, 1, &oh, had_lock);
 	brelse(bh);
 	return status;
-- 
2.12.3