1 From e96b198df364a2918896c41a9759b38aaebcf211 Mon Sep 17 00:00:00 2001
2 From: Gerd Hoffmann <kraxel@redhat.com>
3 Date: Fri, 28 Apr 2017 10:42:37 +0200
4 Subject: [PATCH 13/23] input: limit kbd queue depth
6 Apply a limit to the number of items we accept into the keyboard queue.
8 Impact: Without this limit vnc clients can exhaust host memory by
9 sending keyboard events faster than qemu feeds them to the guest.
12 Cc: P J P <ppandit@redhat.com>
13 Cc: Huawei PSIRT <PSIRT@huawei.com>
14 Reported-by: jiangxin1@huawei.com
15 Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
16 Message-id: 20170428084237.23960-1-kraxel@redhat.com
18 ui/input.c | 14 +++++++++++---
19 1 file changed, 11 insertions(+), 3 deletions(-)
21 diff --git a/ui/input.c b/ui/input.c
22 index ed88cda6d6..fb1f404095 100644
25 @@ -41,6 +41,8 @@ static QTAILQ_HEAD(QemuInputEventQueueHead, QemuInputEventQueue) kbd_queue =
26 QTAILQ_HEAD_INITIALIZER(kbd_queue);
27 static QEMUTimer *kbd_timer;
28 static uint32_t kbd_default_delay_ms = 10;
29 +static uint32_t queue_count;
30 +static uint32_t queue_limit = 1024;
32 QemuInputHandlerState *qemu_input_handler_register(DeviceState *dev,
33 QemuInputHandler *handler)
34 @@ -268,6 +270,7 @@ static void qemu_input_queue_process(void *opaque)
37 QTAILQ_REMOVE(queue, item, node);
42 @@ -282,6 +285,7 @@ static void qemu_input_queue_delay(struct QemuInputEventQueueHead *queue,
43 item->delay_ms = delay_ms;
45 QTAILQ_INSERT_TAIL(queue, item, node);
49 timer_mod(item->timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL)
50 @@ -298,6 +302,7 @@ static void qemu_input_queue_event(struct QemuInputEventQueueHead *queue,
53 QTAILQ_INSERT_TAIL(queue, item, node);
57 static void qemu_input_queue_sync(struct QemuInputEventQueueHead *queue)
58 @@ -306,6 +311,7 @@ static void qemu_input_queue_sync(struct QemuInputEventQueueHead *queue)
60 item->type = QEMU_INPUT_QUEUE_SYNC;
61 QTAILQ_INSERT_TAIL(queue, item, node);
65 void qemu_input_event_send_impl(QemuConsole *src, InputEvent *evt)
66 @@ -381,7 +387,7 @@ void qemu_input_event_send_key(QemuConsole *src, KeyValue *key, bool down)
67 qemu_input_event_send(src, evt);
68 qemu_input_event_sync();
69 qapi_free_InputEvent(evt);
71 + } else if (queue_count < queue_limit) {
72 qemu_input_queue_event(&kbd_queue, src, evt);
73 qemu_input_queue_sync(&kbd_queue);
75 @@ -409,8 +415,10 @@ void qemu_input_event_send_key_delay(uint32_t delay_ms)
76 kbd_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, qemu_input_queue_process,
79 - qemu_input_queue_delay(&kbd_queue, kbd_timer,
80 - delay_ms ? delay_ms : kbd_default_delay_ms);
81 + if (queue_count < queue_limit) {
82 + qemu_input_queue_delay(&kbd_queue, kbd_timer,
83 + delay_ms ? delay_ms : kbd_default_delay_ms);
87 InputEvent *qemu_input_event_new_btn(InputButton btn, bool down)