From 29f5b648fa0b31ad614c78468b9279e5fa96397a Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Fri, 11 Nov 2016 16:22:27 -0300
Subject: Linux-libre 4.8.7-gnu

---
 fs/overlayfs/copy_up.c |  2 ++
 fs/overlayfs/inode.c   |  3 ---
 fs/overlayfs/super.c   | 15 +++++++++++++++
 3 files changed, 17 insertions(+), 3 deletions(-)

(limited to 'fs/overlayfs')

diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index abadbc30e..767377e52 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -171,6 +171,8 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len)
 		len -= bytes;
 	}
 
+	if (!error)
+		error = vfs_fsync(new_file, 0);
 	fput(new_file);
 out_fput:
 	fput(old_file);
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index c75625c1e..cf2bfeb1b 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -294,9 +294,6 @@ struct posix_acl *ovl_get_acl(struct inode *inode, int type)
 	if (!IS_ENABLED(CONFIG_FS_POSIX_ACL) || !IS_POSIXACL(realinode))
 		return NULL;
 
-	if (!realinode->i_op->get_acl)
-		return NULL;
-
 	old_cred = ovl_override_creds(inode->i_sb);
 	acl = get_acl(realinode, type);
 	revert_creds(old_cred);
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index e2a94a267..a78415d77 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -1026,6 +1026,21 @@ ovl_posix_acl_xattr_set(const struct xattr_handler *handler,
 
 	posix_acl_release(acl);
 
+	/*
+	 * Check if sgid bit needs to be cleared (actual setacl operation will
+	 * be done with mounter's capabilities and so that won't do it for us).
+	 */
+	if (unlikely(inode->i_mode & S_ISGID) &&
+	    handler->flags == ACL_TYPE_ACCESS &&
+	    !in_group_p(inode->i_gid) &&
+	    !capable_wrt_inode_uidgid(inode, CAP_FSETID)) {
+		struct iattr iattr = { .ia_valid = ATTR_KILL_SGID };
+
+		err = ovl_setattr(dentry, &iattr);
+		if (err)
+			return err;
+	}
+
 	err = ovl_xattr_set(dentry, handler->name, value, size, flags);
 	if (!err)
 		ovl_copyattr(ovl_inode_real(inode, NULL), inode);
-- 
cgit v1.2.3-54-g00ecf