Merge tag 'nfsd-4.7-2' of git://linux-nfs.org/~bfields/linux

Pull nfsd bugfixes from Bruce Fields:
 "Fix missing server-side permission checks on setting NFS ACLs"

* tag 'nfsd-4.7-2' of git://linux-nfs.org/~bfields/linux:
  nfsd: check permissions when setting ACLs
  posix_acl: Add set_posix_acl
diff --git a/fs/nfsd/nfs2acl.c b/fs/nfsd/nfs2acl.c
index 1580ea6..d08cd88 100644
--- a/fs/nfsd/nfs2acl.c
+++ b/fs/nfsd/nfs2acl.c
@@ -104,22 +104,21 @@
 		goto out;
 
 	inode = d_inode(fh->fh_dentry);
-	if (!IS_POSIXACL(inode) || !inode->i_op->set_acl) {
-		error = -EOPNOTSUPP;
-		goto out_errno;
-	}
 
 	error = fh_want_write(fh);
 	if (error)
 		goto out_errno;
 
-	error = inode->i_op->set_acl(inode, argp->acl_access, ACL_TYPE_ACCESS);
+	fh_lock(fh);
+
+	error = set_posix_acl(inode, ACL_TYPE_ACCESS, argp->acl_access);
 	if (error)
-		goto out_drop_write;
-	error = inode->i_op->set_acl(inode, argp->acl_default,
-				     ACL_TYPE_DEFAULT);
+		goto out_drop_lock;
+	error = set_posix_acl(inode, ACL_TYPE_DEFAULT, argp->acl_default);
 	if (error)
-		goto out_drop_write;
+		goto out_drop_lock;
+
+	fh_unlock(fh);
 
 	fh_drop_write(fh);
 
@@ -131,7 +130,8 @@
 	posix_acl_release(argp->acl_access);
 	posix_acl_release(argp->acl_default);
 	return nfserr;
-out_drop_write:
+out_drop_lock:
+	fh_unlock(fh);
 	fh_drop_write(fh);
 out_errno:
 	nfserr = nfserrno(error);
diff --git a/fs/nfsd/nfs3acl.c b/fs/nfsd/nfs3acl.c
index 01df4cd..0c89034 100644
--- a/fs/nfsd/nfs3acl.c
+++ b/fs/nfsd/nfs3acl.c
@@ -95,22 +95,20 @@
 		goto out;
 
 	inode = d_inode(fh->fh_dentry);
-	if (!IS_POSIXACL(inode) || !inode->i_op->set_acl) {
-		error = -EOPNOTSUPP;
-		goto out_errno;
-	}
 
 	error = fh_want_write(fh);
 	if (error)
 		goto out_errno;
 
-	error = inode->i_op->set_acl(inode, argp->acl_access, ACL_TYPE_ACCESS);
-	if (error)
-		goto out_drop_write;
-	error = inode->i_op->set_acl(inode, argp->acl_default,
-				     ACL_TYPE_DEFAULT);
+	fh_lock(fh);
 
-out_drop_write:
+	error = set_posix_acl(inode, ACL_TYPE_ACCESS, argp->acl_access);
+	if (error)
+		goto out_drop_lock;
+	error = set_posix_acl(inode, ACL_TYPE_DEFAULT, argp->acl_default);
+
+out_drop_lock:
+	fh_unlock(fh);
 	fh_drop_write(fh);
 out_errno:
 	nfserr = nfserrno(error);
diff --git a/fs/nfsd/nfs4acl.c b/fs/nfsd/nfs4acl.c
index 6adabd6..71292a0 100644
--- a/fs/nfsd/nfs4acl.c
+++ b/fs/nfsd/nfs4acl.c
@@ -770,9 +770,6 @@
 	dentry = fhp->fh_dentry;
 	inode = d_inode(dentry);
 
-	if (!inode->i_op->set_acl || !IS_POSIXACL(inode))
-		return nfserr_attrnotsupp;
-
 	if (S_ISDIR(inode->i_mode))
 		flags = NFS4_ACL_DIR;
 
@@ -782,16 +779,19 @@
 	if (host_error < 0)
 		goto out_nfserr;
 
-	host_error = inode->i_op->set_acl(inode, pacl, ACL_TYPE_ACCESS);
+	fh_lock(fhp);
+
+	host_error = set_posix_acl(inode, ACL_TYPE_ACCESS, pacl);
 	if (host_error < 0)
-		goto out_release;
+		goto out_drop_lock;
 
 	if (S_ISDIR(inode->i_mode)) {
-		host_error = inode->i_op->set_acl(inode, dpacl,
-						  ACL_TYPE_DEFAULT);
+		host_error = set_posix_acl(inode, ACL_TYPE_DEFAULT, dpacl);
 	}
 
-out_release:
+out_drop_lock:
+	fh_unlock(fhp);
+
 	posix_acl_release(pacl);
 	posix_acl_release(dpacl);
 out_nfserr:
diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index 8a4a266..edc452c 100644
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -820,6 +820,28 @@
 	return error;
 }
 
+int
+set_posix_acl(struct inode *inode, int type, struct posix_acl *acl)
+{
+	if (!IS_POSIXACL(inode))
+		return -EOPNOTSUPP;
+	if (!inode->i_op->set_acl)
+		return -EOPNOTSUPP;
+
+	if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
+		return acl ? -EACCES : 0;
+	if (!inode_owner_or_capable(inode))
+		return -EPERM;
+
+	if (acl) {
+		int ret = posix_acl_valid(acl);
+		if (ret)
+			return ret;
+	}
+	return inode->i_op->set_acl(inode, acl, type);
+}
+EXPORT_SYMBOL(set_posix_acl);
+
 static int
 posix_acl_xattr_set(const struct xattr_handler *handler,
 		    struct dentry *unused, struct inode *inode,
@@ -829,30 +851,12 @@
 	struct posix_acl *acl = NULL;
 	int ret;
 
-	if (!IS_POSIXACL(inode))
-		return -EOPNOTSUPP;
-	if (!inode->i_op->set_acl)
-		return -EOPNOTSUPP;
-
-	if (handler->flags == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
-		return value ? -EACCES : 0;
-	if (!inode_owner_or_capable(inode))
-		return -EPERM;
-
 	if (value) {
 		acl = posix_acl_from_xattr(&init_user_ns, value, size);
 		if (IS_ERR(acl))
 			return PTR_ERR(acl);
-
-		if (acl) {
-			ret = posix_acl_valid(acl);
-			if (ret)
-				goto out;
-		}
 	}
-
-	ret = inode->i_op->set_acl(inode, acl, handler->flags);
-out:
+	ret = set_posix_acl(inode, handler->flags, acl);
 	posix_acl_release(acl);
 	return ret;
 }