Brad Bishop | d5ae7d9 | 2018-06-14 09:52:03 -0700 | [diff] [blame^] | 1 | From 065061dca34fa5b91be6dce9a87a8755d8826c78 Mon Sep 17 00:00:00 2001 |
Brad Bishop | 316dfdd | 2018-06-25 12:45:53 -0400 | [diff] [blame] | 2 | From: Prasad J Pandit <pjp@fedoraproject.org> |
| 3 | Date: Thu, 16 Nov 2017 13:21:55 +0530 |
| 4 | Subject: [PATCH] ps2: check PS2Queue pointers in post_load routine |
| 5 | |
| 6 | During Qemu guest migration, a destination process invokes ps2 |
| 7 | post_load function. In that, if 'rptr' and 'count' values were |
| 8 | invalid, it could lead to OOB access or infinite loop issue. |
| 9 | Add check to avoid it. |
| 10 | |
| 11 | Reported-by: Cyrille Chatras <cyrille.chatras@orange.com> |
| 12 | Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org> |
| 13 | Message-id: 20171116075155.22378-1-ppandit@redhat.com |
| 14 | Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> |
| 15 | |
| 16 | CVE: CVE-2017-16845 |
| 17 | Upstream-Status: Backport |
| 18 | Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com> |
| 19 | --- |
| 20 | hw/input/ps2.c | 21 +++++++++------------ |
| 21 | 1 file changed, 9 insertions(+), 12 deletions(-) |
| 22 | |
| 23 | diff --git a/hw/input/ps2.c b/hw/input/ps2.c |
| 24 | index f388a23..de171a2 100644 |
| 25 | --- a/hw/input/ps2.c |
| 26 | +++ b/hw/input/ps2.c |
| 27 | @@ -1225,24 +1225,21 @@ static void ps2_common_reset(PS2State *s) |
| 28 | static void ps2_common_post_load(PS2State *s) |
| 29 | { |
| 30 | PS2Queue *q = &s->queue; |
| 31 | - int size; |
| 32 | - int i; |
| 33 | - int tmp_data[PS2_QUEUE_SIZE]; |
| 34 | + uint8_t i, size; |
| 35 | + uint8_t tmp_data[PS2_QUEUE_SIZE]; |
| 36 | |
| 37 | /* set the useful data buffer queue size, < PS2_QUEUE_SIZE */ |
| 38 | - size = q->count > PS2_QUEUE_SIZE ? 0 : q->count; |
| 39 | + size = (q->count < 0 || q->count > PS2_QUEUE_SIZE) ? 0 : q->count; |
| 40 | |
| 41 | /* move the queue elements to the start of data array */ |
| 42 | - if (size > 0) { |
| 43 | - for (i = 0; i < size; i++) { |
| 44 | - /* move the queue elements to the temporary buffer */ |
| 45 | - tmp_data[i] = q->data[q->rptr]; |
| 46 | - if (++q->rptr == 256) { |
| 47 | - q->rptr = 0; |
| 48 | - } |
| 49 | + for (i = 0; i < size; i++) { |
| 50 | + if (q->rptr < 0 || q->rptr >= sizeof(q->data)) { |
| 51 | + q->rptr = 0; |
| 52 | } |
| 53 | - memcpy(q->data, tmp_data, size); |
| 54 | + tmp_data[i] = q->data[q->rptr++]; |
| 55 | } |
| 56 | + memcpy(q->data, tmp_data, size); |
| 57 | + |
| 58 | /* reset rptr/wptr/count */ |
| 59 | q->rptr = 0; |
| 60 | q->wptr = size; |