From ca9e912a28b901387e1dbb85f6c531119f2d5ef2 Mon Sep 17 00:00:00 2001
From: Jakob Unterwurzacher <jakobunt@gmail.com>
Date: Sat, 29 Feb 2020 19:58:08 +0100
Subject: [PATCH] fusefrontend: drop xattr user namespace restriction

We used to restrict setting xattrs to the "user."
namespace. I don't see a real reason for this
anymore, and it causes trouble for users who are using
acls.

Tests will be added in the next commit.

https://github.com/rfjakob/gocryptfs/issues/453
---
 internal/fusefrontend/xattr.go                 | 12 ------------
 internal/fusefrontend/xattr_darwin.go          |  4 ----
 internal/fusefrontend/xattr_linux.go           | 10 ----------
 internal/fusefrontend/xattr_linux_unit_test.go | 13 -------------
 4 files changed, 39 deletions(-)
 delete mode 100644 internal/fusefrontend/xattr_linux_unit_test.go

diff --git a/internal/fusefrontend/xattr.go b/internal/fusefrontend/xattr.go
index 20e8db7..96a0372 100644
--- a/internal/fusefrontend/xattr.go
+++ b/internal/fusefrontend/xattr.go
@@ -27,10 +27,6 @@ func (fs *FS) GetXAttr(relPath string, attr string, context *fuse.Context) ([]by
 	if fs.isFiltered(relPath) {
 		return nil, fuse.EPERM
 	}
-	if disallowedXAttrName(attr) {
-		return nil, _EOPNOTSUPP
-	}
-
 	cAttr := fs.encryptXattrName(attr)
 
 	cData, status := fs.getXAttr(relPath, cAttr, context)
@@ -53,10 +49,6 @@ func (fs *FS) SetXAttr(relPath string, attr string, data []byte, flags int, cont
 	if fs.isFiltered(relPath) {
 		return fuse.EPERM
 	}
-	if disallowedXAttrName(attr) {
-		return _EOPNOTSUPP
-	}
-
 	flags = filterXattrSetFlags(flags)
 	cAttr := fs.encryptXattrName(attr)
 	cData := fs.encryptXattrValue(data)
@@ -70,10 +62,6 @@ func (fs *FS) RemoveXAttr(relPath string, attr string, context *fuse.Context) fu
 	if fs.isFiltered(relPath) {
 		return fuse.EPERM
 	}
-	if disallowedXAttrName(attr) {
-		return _EOPNOTSUPP
-	}
-
 	cAttr := fs.encryptXattrName(attr)
 	return fs.removeXAttr(relPath, cAttr, context)
 }
diff --git a/internal/fusefrontend/xattr_darwin.go b/internal/fusefrontend/xattr_darwin.go
index 741eb6c..b690cc0 100644
--- a/internal/fusefrontend/xattr_darwin.go
+++ b/internal/fusefrontend/xattr_darwin.go
@@ -13,10 +13,6 @@ import (
 	"github.com/rfjakob/gocryptfs/internal/syscallcompat"
 )
 
-func disallowedXAttrName(attr string) bool {
-	return false
-}
-
 // On Darwin it is needed to unset XATTR_NOSECURITY 0x0008
 func filterXattrSetFlags(flags int) int {
 	// See https://opensource.apple.com/source/xnu/xnu-1504.15.3/bsd/sys/xattr.h.auto.html
diff --git a/internal/fusefrontend/xattr_linux.go b/internal/fusefrontend/xattr_linux.go
index 3a64412..b43dfee 100644
--- a/internal/fusefrontend/xattr_linux.go
+++ b/internal/fusefrontend/xattr_linux.go
@@ -5,7 +5,6 @@ package fusefrontend
 
 import (
 	"fmt"
-	"strings"
 	"syscall"
 
 	"golang.org/x/sys/unix"
@@ -15,15 +14,6 @@ import (
 	"github.com/rfjakob/gocryptfs/internal/syscallcompat"
 )
 
-// Only allow the "user" namespace, block "trusted" and "security", as
-// these may be interpreted by the system, and we don't want to cause
-// trouble with our encrypted garbage.
-const xattrUserPrefix = "user."
-
-func disallowedXAttrName(attr string) bool {
-	return !strings.HasPrefix(attr, xattrUserPrefix)
-}
-
 func filterXattrSetFlags(flags int) int {
 	return flags
 }
diff --git a/internal/fusefrontend/xattr_linux_unit_test.go b/internal/fusefrontend/xattr_linux_unit_test.go
deleted file mode 100644
index 5fea58b..0000000
--- a/internal/fusefrontend/xattr_linux_unit_test.go
+++ /dev/null
@@ -1,13 +0,0 @@
-// +build linux
-
-package fusefrontend
-
-import (
-	"testing"
-)
-
-func TestDisallowedLinuxAttributes(t *testing.T) {
-	if !disallowedXAttrName("xxxx") {
-		t.Fatalf("Names that don't start with 'user.' should fail")
-	}
-}