| From 065061dca34fa5b91be6dce9a87a8755d8826c78 Mon Sep 17 00:00:00 2001 |
| From: Prasad J Pandit <pjp@fedoraproject.org> |
| Date: Thu, 16 Nov 2017 13:21:55 +0530 |
| Subject: [PATCH] ps2: check PS2Queue pointers in post_load routine |
| |
| 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 or infinite loop issue. |
| Add check to avoid it. |
| |
| Reported-by: Cyrille Chatras <cyrille.chatras@orange.com> |
| Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org> |
| Message-id: 20171116075155.22378-1-ppandit@redhat.com |
| Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> |
| |
| CVE: CVE-2017-16845 |
| Upstream-Status: Backport |
| Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com> |
| --- |
| hw/input/ps2.c | 21 +++++++++------------ |
| 1 file changed, 9 insertions(+), 12 deletions(-) |
| |
| diff --git a/hw/input/ps2.c b/hw/input/ps2.c |
| index f388a23..de171a2 100644 |
| --- a/hw/input/ps2.c |
| +++ b/hw/input/ps2.c |
| @@ -1225,24 +1225,21 @@ static void ps2_common_reset(PS2State *s) |
| static void ps2_common_post_load(PS2State *s) |
| { |
| PS2Queue *q = &s->queue; |
| - int size; |
| - int i; |
| - int tmp_data[PS2_QUEUE_SIZE]; |
| + uint8_t i, size; |
| + uint8_t tmp_data[PS2_QUEUE_SIZE]; |
| |
| /* set the useful data buffer queue size, < PS2_QUEUE_SIZE */ |
| - size = q->count > PS2_QUEUE_SIZE ? 0 : q->count; |
| + size = (q->count < 0 || 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++) { |
| + if (q->rptr < 0 || q->rptr >= sizeof(q->data)) { |
| + q->rptr = 0; |
| } |
| - memcpy(q->data, tmp_data, size); |
| + tmp_data[i] = q->data[q->rptr++]; |
| } |
| + memcpy(q->data, tmp_data, size); |
| + |
| /* reset rptr/wptr/count */ |
| q->rptr = 0; |
| q->wptr = size; |