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[Qemu-devel] [PATCH v2] ps2: check PS2Queue indices in post_load routine
From: |
P J P |
Subject: |
[Qemu-devel] [PATCH v2] ps2: check PS2Queue indices in post_load routine |
Date: |
Thu, 16 Nov 2017 15:46:55 +0530 |
From: Prasad J Pandit <address@hidden>
During Qemu guest migration, a destination process invokes ps2
post_load function. In that, if 'rptr' and 'count' values were
invalid, it could lead to OOB access issue. Add check to avoid
it.
Reported-by: Cyrille Chatras <address@hidden>
Signed-off-by: Prasad J Pandit <address@hidden>
---
hw/input/ps2.c | 39 ++++++++++++++++++---------------------
1 file changed, 18 insertions(+), 21 deletions(-)
Update: return -1(bad indices) error, instead of correcting values
-> https://lists.gnu.org/archive/html/qemu-devel/2017-11/msg02964.html
diff --git a/hw/input/ps2.c b/hw/input/ps2.c
index f388a23c8e..35392d55fc 100644
--- a/hw/input/ps2.c
+++ b/hw/input/ps2.c
@@ -1222,32 +1222,37 @@ static void ps2_common_reset(PS2State *s)
s->update_irq(s->update_arg, 0);
}
-static void ps2_common_post_load(PS2State *s)
+static int ps2_common_post_load(PS2State *s)
{
PS2Queue *q = &s->queue;
int size;
int i;
int tmp_data[PS2_QUEUE_SIZE];
+ if (q->count < 0 || q->rptr < 0 || q->rptr >= sizeof(q->data)) {
+ return -1;
+ }
+
/* set the useful data buffer queue size, < PS2_QUEUE_SIZE */
size = q->count > PS2_QUEUE_SIZE ? 0 : q->count;
/* move the queue elements to the start of data array */
- if (size > 0) {
- for (i = 0; i < size; i++) {
- /* move the queue elements to the temporary buffer */
- tmp_data[i] = q->data[q->rptr];
- if (++q->rptr == 256) {
- q->rptr = 0;
- }
+ for (i = 0; i < size; i++) {
+ /* move the queue elements to the temporary buffer */
+ tmp_data[i] = q->data[q->rptr];
+ if (++q->rptr == 256) {
+ q->rptr = 0;
}
- memcpy(q->data, tmp_data, size);
}
+ memcpy(q->data, tmp_data, size);
+
/* reset rptr/wptr/count */
q->rptr = 0;
q->wptr = size;
q->count = size;
s->update_irq(s->update_arg, q->count != 0);
+
+ return 0;
}
static void ps2_kbd_reset(void *opaque)
@@ -1346,9 +1351,7 @@ static int ps2_kbd_post_load(void* opaque, int version_id)
if (version_id == 2)
s->scancode_set=2;
- ps2_common_post_load(ps2);
-
- return 0;
+ return ps2_common_post_load(ps2);
}
static int ps2_kbd_pre_save(void *opaque)
@@ -1356,9 +1359,7 @@ static int ps2_kbd_pre_save(void *opaque)
PS2KbdState *s = (PS2KbdState *)opaque;
PS2State *ps2 = &s->common;
- ps2_common_post_load(ps2);
-
- return 0;
+ return ps2_common_post_load(ps2);
}
static const VMStateDescription vmstate_ps2_keyboard = {
@@ -1386,9 +1387,7 @@ static int ps2_mouse_post_load(void *opaque, int
version_id)
PS2MouseState *s = (PS2MouseState *)opaque;
PS2State *ps2 = &s->common;
- ps2_common_post_load(ps2);
-
- return 0;
+ return ps2_common_post_load(ps2);
}
static int ps2_mouse_pre_save(void *opaque)
@@ -1396,9 +1395,7 @@ static int ps2_mouse_pre_save(void *opaque)
PS2MouseState *s = (PS2MouseState *)opaque;
PS2State *ps2 = &s->common;
- ps2_common_post_load(ps2);
-
- return 0;
+ return ps2_common_post_load(ps2);
}
static const VMStateDescription vmstate_ps2_mouse = {
--
2.13.6
- [Qemu-devel] [PATCH v2] ps2: check PS2Queue indices in post_load routine,
P J P <=