Module Name: src
Committed By: kamil
Date: Sun Apr 5 15:16:11 UTC 2020
Modified Files:
src/sys/rump/librump/rumpkern: rumpcopy.c
Log Message:
Return early on 0-sized transfers (usually to/from NULL-objects)
This logic is already present in subr_copy.c:copyin_vmspace() and
rumpcopy.c:copyinstr().
This avoids memcpy() calls for NULL objects that is Undefined Behavior,
allowed in the kernel space (-fno-delete-null-pointer-checks), but not
in userland.
Reported by UBSan.
To generate a diff of this commit:
cvs rdiff -u -r1.23 -r1.24 src/sys/rump/librump/rumpkern/rumpcopy.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/rump/librump/rumpkern/rumpcopy.c
diff -u src/sys/rump/librump/rumpkern/rumpcopy.c:1.23 src/sys/rump/librump/rumpkern/rumpcopy.c:1.24
--- src/sys/rump/librump/rumpkern/rumpcopy.c:1.23 Sat Apr 6 03:06:28 2019
+++ src/sys/rump/librump/rumpkern/rumpcopy.c Sun Apr 5 15:16:11 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: rumpcopy.c,v 1.23 2019/04/06 03:06:28 thorpej Exp $ */
+/* $NetBSD: rumpcopy.c,v 1.24 2020/04/05 15:16:11 kamil Exp $ */
/*
* Copyright (c) 2009 Antti Kantee. All Rights Reserved.
@@ -26,7 +26,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: rumpcopy.c,v 1.23 2019/04/06 03:06:28 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: rumpcopy.c,v 1.24 2020/04/05 15:16:11 kamil Exp $");
#define __UFETCHSTORE_PRIVATE
#define __UCAS_PRIVATE
@@ -45,6 +45,9 @@ copyin(const void *uaddr, void *kaddr, s
{
int error = 0;
+ if (len == 0)
+ return 0;
+
if (__predict_false(uaddr == NULL && len)) {
return EFAULT;
}
@@ -64,6 +67,9 @@ copyout(const void *kaddr, void *uaddr,
{
int error = 0;
+ if (len == 0)
+ return 0;
+
if (__predict_false(uaddr == NULL && len)) {
return EFAULT;
}
@@ -137,6 +143,9 @@ copyoutstr(const void *kaddr, void *uadd
size_t slen;
int error;
+ if (len == 0)
+ return 0;
+
if (__predict_false(uaddr == NULL && len)) {
return EFAULT;
}
@@ -160,6 +169,9 @@ int
kcopy(const void *src, void *dst, size_t len)
{
+ if (len == 0)
+ return 0;
+
memcpy(dst, src, len);
return 0;
}
