Aren
/
NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

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.
This commit is contained in:
kamil 2020-04-05 15:16:11 +00:00
parent b6924e8af2
commit 17a313ddde
1 changed files with 14 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
sys/rump/librump/rumpkern/rumpcopy.c
View File

@ -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, size_t len)
{
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, size_t len)
{
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 *uaddr, size_t len, size_t *done)
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;
}