debian/patches/extra/0013-input-limit-kbd-queue-depth.patch

   1 From e4f39e928710d19db0a0669b66520236197352aa 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 13/15] input: limit kbd queue depth
   5
   6 Apply a limit to the number of items we accept into the keyboard queue.
   7
   8 Impact: Without this limit vnc clients can exhaust host memory by
   9 sending keyboard events faster than qemu feeds them to the guest.
  10
  11 Fixes: CVE-2017-8379
  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
  17 ---
  18  ui/input.c | 14 +++++++++++---
  19  1 file changed, 11 insertions(+), 3 deletions(-)
  20
  21 diff --git a/ui/input.c b/ui/input.c
  22 index ed88cda6d6..fb1f404095 100644
  23 --- a/ui/input.c
  24 +++ b/ui/input.c
  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;
  31
  32  QemuInputHandlerState *qemu_input_handler_register(DeviceState *dev,
  33                                                     QemuInputHandler *handler)
  34 @@ -268,6 +270,7 @@ static void qemu_input_queue_process(void *opaque)
  35              break;
  36          }
  37          QTAILQ_REMOVE(queue, item, node);
  38 +        queue_count--;
  39          g_free(item);
  40      }
  41  }
  42 @@ -282,6 +285,7 @@ static void qemu_input_queue_delay(struct QemuInputEventQueueHead *queue,
  43      item->delay_ms = delay_ms;
  44      item->timer = timer;
  45      QTAILQ_INSERT_TAIL(queue, item, node);
  46 +    queue_count++;
  47
  48      if (start_timer) {
  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,
  51      item->src = src;
  52      item->evt = evt;
  53      QTAILQ_INSERT_TAIL(queue, item, node);
  54 +    queue_count++;
  55  }
  56
  57  static void qemu_input_queue_sync(struct QemuInputEventQueueHead *queue)
  58 @@ -306,6 +311,7 @@ static void qemu_input_queue_sync(struct QemuInputEventQueueHead *queue)
  59
  60      item->type = QEMU_INPUT_QUEUE_SYNC;
  61      QTAILQ_INSERT_TAIL(queue, item, node);
  62 +    queue_count++;
  63  }
  64
  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);
  70 -    } else {
  71 +    } else if (queue_count < queue_limit) {
  72          qemu_input_queue_event(&kbd_queue, src, evt);
  73          qemu_input_queue_sync(&kbd_queue);
  74      }
  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,
  77                                   &kbd_queue);
  78      }
  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);
  84 +    }
  85  }
  86
  87  InputEvent *qemu_input_event_new_btn(InputButton btn, bool down)
  88 --
  89 2.11.0
  90