From c0d727dfed74f197b5e477887bb671a130477dc7 Mon Sep 17 00:00:00 2001
From: Michael Eischer <michael.eischer@fau.de>
Date: Sat, 16 Nov 2024 20:56:59 +0100
Subject: [PATCH] fs: correctly handle O_NOFOLLOW for xattr / generic attribute
 retrieval

---
 internal/fs/ea_windows_test.go |  4 ++--
 internal/fs/meta_windows.go    |  4 ++--
 internal/fs/meta_xattr.go      | 14 ++++++++++++--
 internal/fs/node_xattr.go      | 13 +++++++++++++
 4 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/internal/fs/ea_windows_test.go b/internal/fs/ea_windows_test.go
index a1f940b49..b5f7d109f 100644
--- a/internal/fs/ea_windows_test.go
+++ b/internal/fs/ea_windows_test.go
@@ -262,7 +262,7 @@ func TestPathSupportsExtendedAttributes(t *testing.T) {
 
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
-			handle, err := openMetadataHandle(tc.path, false)
+			handle, err := openMetadataHandle(tc.path, 0)
 			rtest.OK(t, err)
 			supported, err := handleSupportsExtendedAttributes(windows.Handle(handle.Fd()))
 			if err != nil {
@@ -276,7 +276,7 @@ func TestPathSupportsExtendedAttributes(t *testing.T) {
 
 	// Test with an invalid path
 
-	handle, err := openMetadataHandle("Z:\\NonExistentPath-UAS664da5s4dyu56das45f5as", false)
+	handle, err := openMetadataHandle("Z:\\NonExistentPath-UAS664da5s4dyu56das45f5as", 0)
 	rtest.OK(t, err)
 	_, err = handleSupportsExtendedAttributes(windows.Handle(handle.Fd()))
 	if err == nil {
diff --git a/internal/fs/meta_windows.go b/internal/fs/meta_windows.go
index d6edeb939..62d859439 100644
--- a/internal/fs/meta_windows.go
+++ b/internal/fs/meta_windows.go
@@ -11,7 +11,7 @@ import (
 )
 
 func (p *pathMetadataHandle) Xattr(_ bool) ([]restic.ExtendedAttribute, error) {
-	f, err := openMetadataHandle(p.name, false)
+	f, err := openMetadataHandle(p.name, p.flag)
 	if err != nil {
 		return nil, err
 	}
@@ -54,7 +54,7 @@ func xattrFromHandle(path string, handle windows.Handle) ([]restic.ExtendedAttri
 }
 
 func (p *pathMetadataHandle) SecurityDescriptor() (buf *[]byte, err error) {
-	f, err := openMetadataHandle(p.name, 0)
+	f, err := openMetadataHandle(p.name, p.flag)
 	if err != nil {
 		return nil, err
 	}
diff --git a/internal/fs/meta_xattr.go b/internal/fs/meta_xattr.go
index 224154cb1..9e762bd3d 100644
--- a/internal/fs/meta_xattr.go
+++ b/internal/fs/meta_xattr.go
@@ -15,8 +15,18 @@ func (p *pathMetadataHandle) Xattr(ignoreListError bool) ([]restic.ExtendedAttri
 	path := p.Name()
 	return xattrFromPath(
 		path,
-		func() ([]string, error) { return listxattr(path) },
-		func(attr string) ([]byte, error) { return getxattr(path, attr) },
+		func() ([]string, error) {
+			if (p.flag & O_NOFOLLOW) != 0 {
+				return llistxattr(path)
+			}
+			return listxattr(path)
+		},
+		func(attr string) ([]byte, error) {
+			if (p.flag & O_NOFOLLOW) != 0 {
+				return lgetxattr(path, attr)
+			}
+			return getxattr(path, attr)
+		},
 		ignoreListError,
 	)
 }
diff --git a/internal/fs/node_xattr.go b/internal/fs/node_xattr.go
index 988c37845..7becbd10b 100644
--- a/internal/fs/node_xattr.go
+++ b/internal/fs/node_xattr.go
@@ -51,6 +51,12 @@ func fgetxattr(f *os.File, name string) (b []byte, err error) {
 
 // getxattr retrieves extended attribute data associated with path.
 func getxattr(path string, name string) (b []byte, err error) {
+	b, err = xattr.Get(path, name)
+	return b, handleXattrErr(err)
+}
+
+// lgetxattr retrieves extended attribute data associated with path.
+func lgetxattr(path string, name string) (b []byte, err error) {
 	b, err = xattr.LGet(path, name)
 	return b, handleXattrErr(err)
 }
@@ -70,6 +76,13 @@ func flistxattr(f *os.File) (l []string, err error) {
 // listxattr retrieves a list of names of extended attributes associated with the
 // given path in the file system.
 func listxattr(path string) ([]string, error) {
+	l, err := xattr.List(path)
+	return l, handleXattrErr(err)
+}
+
+// llistxattr retrieves a list of names of extended attributes associated with the
+// given path in the file system.
+func llistxattr(path string) ([]string, error) {
 	l, err := xattr.LList(path)
 	return l, handleXattrErr(err)
 }