From 77ef9c7e79a8e8d948c11330584ea205b35bb0e1 Mon Sep 17 00:00:00 2001

From: Brad Fitzpatrick <[email protected]>

Date: Sat, 2 Apr 2016 00:20:13 +0000

Subject: [PATCH 77/79] syscall: point to x/sys in DLL loading docs, update

 syscall generator

Updates the syscall generator for patchset 4 of https://golang.org/cl/21388.

Updates #14959

Change-Id: Icbd6df489887d3dcc076dfc73d4feb1376abaf8b

Reviewed-on: https://go-review.googlesource.com/21428

Reviewed-by: Alex Brainman <[email protected]>

Reviewed-on: https://go-review.googlesource.com/21680

Reviewed-by: Brad Fitzpatrick <[email protected]>

---

 src/syscall/dll_windows.go       | 13 +++++++++++++

 src/syscall/mksyscall_windows.go |  4 ++--

 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/syscall/dll_windows.go b/src/syscall/dll_windows.go

index ec8d85b..453ec11 100644

--- a/src/syscall/dll_windows.go

+++ b/src/syscall/dll_windows.go

@@ -37,6 +37,13 @@ type DLL struct {

 }

 // LoadDLL loads the named DLL file into memory.

+//

+// If name is not an absolute path and is not a known system DLL used by

+// Go, Windows will search for the named DLL in many locations, causing

+// potential DLL preloading attacks.

+//

+// Use LazyDLL in golang.org/x/sys/windows for a secure way to

+// load system DLLs.

 func LoadDLL(name string) (*DLL, error) {

 	namep, err := UTF16PtrFromString(name)

 	if err != nil {

@@ -174,6 +181,12 @@ func (p *Proc) Call(a ...uintptr) (r1, r2 uintptr, lastErr error) {

 // It will delay the load of the DLL until the first

 // call to its Handle method or to one of its

 // LazyProc's Addr method.

+//

+// LazyDLL is subject to the same DLL preloading attacks as documented

+// on LoadDLL.

+//

+// Use LazyDLL in golang.org/x/sys/windows for a secure way to

+// load system DLLs.

 type LazyDLL struct {

 	mu   sync.Mutex

 	dll  *DLL // non nil once DLL is loaded

diff --git a/src/syscall/mksyscall_windows.go b/src/syscall/mksyscall_windows.go

index 546cb0d..7786d13 100644

--- a/src/syscall/mksyscall_windows.go

+++ b/src/syscall/mksyscall_windows.go

@@ -707,9 +707,9 @@ func (src *Source) Generate(w io.Writer) error {

 			}

 			if *sysRepo {

 				if packageName == "windows" {

-					return "&LazyDLL{Name: " + arg + ", Flags: LoadLibrarySearchSystem32}"

+					return "&LazyDLL{Name: " + arg + ", System: true}"

 				} else {

-					return "&windows.LazyDLL{Name: " + arg + ", Flags: windows.LoadLibrarySearchSystem32}"

+					return "&windows.LazyDLL{Name: " + arg + ", System: true}"

 				}

 			} else {

 				return syscalldot() + "NewLazyDLL(" + arg + ")"

-- 

2.7.4