Module Name: src
Committed By: kamil
Date: Thu Nov 7 18:30:27 UTC 2019
Modified Files:
src/sys/kern: subr_disk_mbr.c
Log Message:
Ensure in validate_label() that struct disklabel pointer is 8-byte aligned
The label is searched each 4 bytes and can be detected in an unaligned
location. Before any operations on it, copy it to promptly aligned local
copy on the stack.
This is a missing part of the following change:
revision 1.108
date: 2011-01-18 20:52:24 +0100; author: matt; state: Exp; lines: +2 -1;
Make struct disklabel 8 byte aligned. This increases its size by 4 bytes
on IPL32 platforms so add code in sys_ioctl (and netbsd32_ioctl) to deal
with the older/smaller diskabel size. This change makes disklabel the
same for both IPL32 and LP64 platforms
OK by <martin>
To generate a diff of this commit:
cvs rdiff -u -r1.52 -r1.53 src/sys/kern/subr_disk_mbr.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/kern/subr_disk_mbr.c
diff -u src/sys/kern/subr_disk_mbr.c:1.52 src/sys/kern/subr_disk_mbr.c:1.53
--- src/sys/kern/subr_disk_mbr.c:1.52 Wed Nov 6 13:07:32 2019
+++ src/sys/kern/subr_disk_mbr.c Thu Nov 7 18:30:27 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: subr_disk_mbr.c,v 1.52 2019/11/06 13:07:32 kamil Exp $ */
+/* $NetBSD: subr_disk_mbr.c,v 1.53 2019/11/07 18:30:27 kamil Exp $ */
/*
* Copyright (c) 1982, 1986, 1988 Regents of the University of California.
@@ -54,7 +54,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_disk_mbr.c,v 1.52 2019/11/06 13:07:32 kamil Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_disk_mbr.c,v 1.53 2019/11/07 18:30:27 kamil Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -588,7 +588,7 @@ check_label_magic(const struct disklabel
static int
validate_label(mbr_args_t *a, uint label_sector)
{
- struct disklabel *dlp;
+ struct disklabel *dlp, tlp;
char *dlp_lim, *dlp_byte;
int error;
#ifdef DISKLABEL_EI
@@ -624,21 +624,23 @@ validate_label(mbr_args_t *a, uint label
else
dlp_byte += LABELSECTOR * a->lp->d_secsize;
dlp = (void *)dlp_byte;
+ memcpy(&tlp, dlp, sizeof(tlp));
break;
}
- if (!check_label_magic(dlp, DISKMAGIC))
+ memcpy(&tlp, dlp, sizeof(tlp));
+ if (!check_label_magic(&tlp, DISKMAGIC))
#ifdef DISKLABEL_EI
{
- if (!check_label_magic(dlp, bswap32(DISKMAGIC)))
+ if (!check_label_magic(&tlp, bswap32(DISKMAGIC)))
continue;
/*
* The label is in the other byte order. We need to
* checksum before swapping the byte order.
*/
- npartitions = bswap16(dlp->d_npartitions);
+ npartitions = bswap16(tlp.d_npartitions);
if (npartitions > MAXPARTITIONS ||
- dkcksum_sized(dlp, npartitions) != 0)
+ dkcksum_sized(&tlp, npartitions) != 0)
goto corrupted;
swapped = 1;
@@ -646,8 +648,8 @@ validate_label(mbr_args_t *a, uint label
#else
continue;
#endif
- else if (dlp->d_npartitions > MAXPARTITIONS ||
- dkcksum(dlp) != 0) {
+ else if (tlp.d_npartitions > MAXPARTITIONS ||
+ dkcksum(&tlp) != 0) {
#ifdef DISKLABEL_EI
corrupted:
#endif
@@ -661,11 +663,11 @@ corrupted:
case READ_LABEL:
#ifdef DISKLABEL_EI
if (swapped)
- swap_disklabel(a->lp, dlp);
+ swap_disklabel(a->lp, &tlp);
else
- *a->lp = *dlp;
+ *a->lp = tlp;
#else
- *a->lp = *dlp;
+ *a->lp = tlp;
#endif
if ((a->msg = convertdisklabel(a->lp, a->strat, a->bp,
a->secperunit)) != NULL)
@@ -677,12 +679,13 @@ corrupted:
#ifdef DISKLABEL_EI
/* DO NOT swap a->lp itself for later references. */
if (swapped)
- swap_disklabel(dlp, a->lp);
+ swap_disklabel(&tlp, a->lp);
else
- *dlp = *a->lp;
+ tlp = *a->lp;
#else
- *dlp = *a->lp;
+ tlp = *a->lp;
#endif
+ memcpy(dlp, &tlp, sizeof(tlp));
a->bp->b_oflags &= ~BO_DONE;
a->bp->b_flags &= ~B_READ;
a->bp->b_flags |= B_WRITE;
