1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
|
$NetBSD: patch-XSA-197,v 1.1 2016/12/29 23:12:23 wiz Exp $
Backported from:
From: Jan Beulich <jbeulich@suse.com>
Subject: xen: fix ioreq handling
Avoid double fetches and bounds check size to avoid overflowing
internal variables.
This is XSA-197.
Reported-by: yanghongke <yanghongke@huawei.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Ian Jackson <ian.jackson@eu.citrix.com>
--- ioemu-qemu-xen/i386-dm/helper2.c.orig 2013-07-17 12:59:40.000000000 +0200
+++ ioemu-qemu-xen/i386-dm/helper2.c 2016-11-22 16:15:32.000000000 +0100
@@ -333,6 +333,11 @@
sign = req->df ? -1 : 1;
+ if (req->size > sizeof(unsigned long)) {
+ fprintf(stderr, "PIO: bad size (%u)\n", req->size);
+ exit(-1);
+ }
+
if (req->dir == IOREQ_READ) {
if (!req->data_is_ptr) {
req->data = do_inp(env, req->addr, req->size);
@@ -368,6 +373,11 @@
sign = req->df ? -1 : 1;
+ if (req->size > sizeof(req->data)) {
+ fprintf(stderr, "MMIO: bad size (%u)\n", req->size);
+ exit(-1);
+ }
+
if (!req->data_is_ptr) {
if (req->dir == IOREQ_READ) {
for (i = 0; i < req->count; i++) {
@@ -481,11 +491,13 @@
req.df = 1;
req.type = buf_req->type;
req.data_is_ptr = 0;
+ xen_rmb();
qw = (req.size == 8);
if (qw) {
buf_req = &buffered_io_page->buf_ioreq[
(buffered_io_page->read_pointer+1) % IOREQ_BUFFER_SLOT_NUM];
req.data |= ((uint64_t)buf_req->data) << 32;
+ xen_rmb();
}
__handle_ioreq(env, &req);
@@ -512,7 +524,11 @@
__handle_buffered_iopage(env);
if (req) {
- __handle_ioreq(env, req);
+ ioreq_t copy = *req;
+
+ xen_rmb();
+ __handle_ioreq(env, ©);
+ req->data = copy.data;
if (req->state != STATE_IOREQ_INPROCESS) {
fprintf(logfile, "Badness in I/O request ... not in service?!: "
|
