1 files changed, 56 insertions, 18 deletions

diff --git a/src/pkg/syscall/exec_unix.go b/src/pkg/syscall/exec_unix.go
index dfaa0374a..01b76c106 100644
--- a/src/pkg/syscall/exec_unix.go
+++ b/src/pkg/syscall/exec_unix.go
@@ -63,8 +63,9 @@ import (
 
 var ForkLock sync.RWMutex
 
-// Convert array of string to array
-// of NUL-terminated byte pointer.
+// StringSlicePtr is deprecated. Use SlicePtrFromStrings instead.
+// If any string contains a NUL byte this function panics instead
+// of returning an error.
 func StringSlicePtr(ss []string) []*byte {
 	bb := make([]*byte, len(ss)+1)
 	for i := 0; i < len(ss); i++ {
@@ -74,6 +75,22 @@ func StringSlicePtr(ss []string) []*byte {
 	return bb
 }
 
+// SlicePtrFromStrings converts a slice of strings to a slice of
+// pointers to NUL-terminated byte slices. If any string contains
+// a NUL byte, it returns (nil, EINVAL).
+func SlicePtrFromStrings(ss []string) ([]*byte, error) {
+	var err error
+	bb := make([]*byte, len(ss)+1)
+	for i := 0; i < len(ss); i++ {
+		bb[i], err = BytePtrFromString(ss[i])
+		if err != nil {
+			return nil, err
+		}
+	}
+	bb[len(ss)] = nil
+	return bb, nil
+}
+
 func CloseOnExec(fd int) { fcntl(fd, F_SETFD, FD_CLOEXEC) }
 
 func SetNonblock(fd int, nonblocking bool) (err error) {
@@ -128,9 +145,18 @@ func forkExec(argv0 string, argv []string, attr *ProcAttr) (pid int, err error)
 	p[1] = -1
 
 	// Convert args to C form.
-	argv0p := StringBytePtr(argv0)
-	argvp := StringSlicePtr(argv)
-	envvp := StringSlicePtr(attr.Env)
+	argv0p, err := BytePtrFromString(argv0)
+	if err != nil {
+		return 0, err
+	}
+	argvp, err := SlicePtrFromStrings(argv)
+	if err != nil {
+		return 0, err
+	}
+	envvp, err := SlicePtrFromStrings(attr.Env)
+	if err != nil {
+		return 0, err
+	}
 
 	if runtime.GOOS == "freebsd" && len(argv[0]) > len(argv0) {
 		argvp[0] = argv0p
@@ -138,11 +164,17 @@ func forkExec(argv0 string, argv []string, attr *ProcAttr) (pid int, err error)
 
 	var chroot *byte
 	if sys.Chroot != "" {
-		chroot = StringBytePtr(sys.Chroot)
+		chroot, err = BytePtrFromString(sys.Chroot)
+		if err != nil {
+			return 0, err
+		}
 	}
 	var dir *byte
 	if attr.Dir != "" {
-		dir = StringBytePtr(attr.Dir)
+		dir, err = BytePtrFromString(attr.Dir)
+		if err != nil {
+			return 0, err
+		}
 	}
 
 	// Acquire the fork lock so that no other threads
@@ -151,13 +183,7 @@ func forkExec(argv0 string, argv []string, attr *ProcAttr) (pid int, err error)
 	ForkLock.Lock()
 
 	// Allocate child status pipe close on exec.
-	if err = Pipe(p[0:]); err != nil {
-		goto error
-	}
-	if _, err = fcntl(p[0], F_SETFD, FD_CLOEXEC); err != nil {
-		goto error
-	}
-	if _, err = fcntl(p[1], F_SETFD, FD_CLOEXEC); err != nil {
+	if err = forkExecPipe(p[:]); err != nil {
 		goto error
 	}
 
@@ -171,7 +197,7 @@ func forkExec(argv0 string, argv []string, attr *ProcAttr) (pid int, err error)
 
 	// Read child error status from pipe.
 	Close(p[1])
-	n, err = read(p[0], (*byte)(unsafe.Pointer(&err1)), int(unsafe.Sizeof(err1)))
+	n, err = readlen(p[0], (*byte)(unsafe.Pointer(&err1)), int(unsafe.Sizeof(err1)))
 	Close(p[0])
 	if err != nil || n != 0 {
 		if n == int(unsafe.Sizeof(err1)) {
@@ -215,9 +241,21 @@ func StartProcess(argv0 string, argv []string, attr *ProcAttr) (pid int, handle
 
 // Ordinary exec.
 func Exec(argv0 string, argv []string, envv []string) (err error) {
+	argv0p, err := BytePtrFromString(argv0)
+	if err != nil {
+		return err
+	}
+	argvp, err := SlicePtrFromStrings(argv)
+	if err != nil {
+		return err
+	}
+	envvp, err := SlicePtrFromStrings(envv)
+	if err != nil {
+		return err
+	}
 	_, _, err1 := RawSyscall(SYS_EXECVE,
-		uintptr(unsafe.Pointer(StringBytePtr(argv0))),
-		uintptr(unsafe.Pointer(&StringSlicePtr(argv)[0])),
-		uintptr(unsafe.Pointer(&StringSlicePtr(envv)[0])))
+		uintptr(unsafe.Pointer(argv0p)),
+		uintptr(unsafe.Pointer(&argvp[0])),
+		uintptr(unsafe.Pointer(&envvp[0])))
 	return Errno(err1)
 }