btrfs: Don't clear SGID when inheriting ACLs

jankara · kdave · commit b7f8a09f8097 · 2017-06-29T20:24:59.000+02:00
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 __btrfs_set_acl() into btrfs_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. Fixes: 0739310 CC: stable@vger.kernel.org CC: linux-btrfs@vger.kernel.org CC: David Sterba <dsterba@suse.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
@@ -78,12 +78,6 @@ static int __btrfs_set_acl(struct btrfs_trans_handle *trans,
 	switch (type) {
 	case ACL_TYPE_ACCESS:
 		name = XATTR_NAME_POSIX_ACL_ACCESS;
-		if (acl) {
-			ret = posix_acl_update_mode(inode, &inode->i_mode, &acl);
-			if (ret)
-				return ret;
-		}
-		ret = 0;
 		break;
 	case ACL_TYPE_DEFAULT:
 		if (!S_ISDIR(inode->i_mode))
@@ -119,6 +113,13 @@ static int __btrfs_set_acl(struct btrfs_trans_handle *trans,
 
 int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 {
+	int ret;
+
+	if (type == ACL_TYPE_ACCESS && acl) {
+		ret = posix_acl_update_mode(inode, &inode->i_mode, &acl);
+		if (ret)
+			return ret;
+	}
 	return __btrfs_set_acl(NULL, inode, acl, type);
 }
 
