* [Qemu-devel] [PATCH v2] virtio-serial: fix heap-over-flow
@ 2018-03-28 13:34 linzhecheng
2018-04-04 9:53 ` Stefan Hajnoczi
0 siblings, 1 reply; 3+ messages in thread
From: linzhecheng @ 2018-03-28 13:34 UTC (permalink / raw)
To: qemu-devel; +Cc: pbonzini, mst, amit.shah, wangxinxin.wang, linzhecheng
Check device having the feature of VIRTIO_CONSOLE_F_EMERG_WRITE before
get config->emerg_wr. It is neccessary because sizeof(virtio_console_config)
is 8 byte if VirtIOSerial doesn't have the feature of
VIRTIO_CONSOLE_F_EMERG_WRITE(see virtio_serial_device_realize),
read/write emerg_wr will lead to heap-over-flow.
Signed-off-by: linzhecheng <linzhecheng@huawei.com>
diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c
index 9470bd7be7..d2dd8ab502 100644
--- a/hw/char/virtio-serial-bus.c
+++ b/hw/char/virtio-serial-bus.c
@@ -580,13 +580,16 @@ static void set_config(VirtIODevice *vdev, const uint8_t *config_data)
VirtIOSerial *vser = VIRTIO_SERIAL(vdev);
struct virtio_console_config *config =
(struct virtio_console_config *)config_data;
- uint8_t emerg_wr_lo = le32_to_cpu(config->emerg_wr);
VirtIOSerialPort *port = find_first_connected_console(vser);
VirtIOSerialPortClass *vsc;
+ uint8_t emerg_wr_lo;
- if (!config->emerg_wr) {
+ if (!virtio_has_feature(vser->host_features,
+ VIRTIO_CONSOLE_F_EMERG_WRITE) || !config->emerg_wr) {
return;
}
+
+ emerg_wr_lo = le32_to_cpu(config->emerg_wr);
/* Make sure we don't misdetect an emergency write when the guest
* does a short config write after an emergency write. */
config->emerg_wr = 0;
--
2.12.2.windows.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] [PATCH v2] virtio-serial: fix heap-over-flow
2018-03-28 13:34 [Qemu-devel] [PATCH v2] virtio-serial: fix heap-over-flow linzhecheng
@ 2018-04-04 9:53 ` Stefan Hajnoczi
2018-04-04 14:22 ` Michael S. Tsirkin
0 siblings, 1 reply; 3+ messages in thread
From: Stefan Hajnoczi @ 2018-04-04 9:53 UTC (permalink / raw)
To: pbonzini, mst; +Cc: qemu-devel, amit.shah, wangxinxin.wang, linzhecheng
[-- Attachment #1: Type: text/plain, Size: 553 bytes --]
On Wed, Mar 28, 2018 at 09:34:35PM +0800, linzhecheng wrote:
> Check device having the feature of VIRTIO_CONSOLE_F_EMERG_WRITE before
> get config->emerg_wr. It is neccessary because sizeof(virtio_console_config)
> is 8 byte if VirtIOSerial doesn't have the feature of
> VIRTIO_CONSOLE_F_EMERG_WRITE(see virtio_serial_device_realize),
> read/write emerg_wr will lead to heap-over-flow.
>
> Signed-off-by: linzhecheng <linzhecheng@huawei.com>
Michael or Paolo: Please merge for QEMU 2.12
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] [PATCH v2] virtio-serial: fix heap-over-flow
2018-04-04 9:53 ` Stefan Hajnoczi
@ 2018-04-04 14:22 ` Michael S. Tsirkin
0 siblings, 0 replies; 3+ messages in thread
From: Michael S. Tsirkin @ 2018-04-04 14:22 UTC (permalink / raw)
To: Stefan Hajnoczi
Cc: pbonzini, qemu-devel, amit.shah, wangxinxin.wang, linzhecheng
On Wed, Apr 04, 2018 at 10:53:22AM +0100, Stefan Hajnoczi wrote:
> On Wed, Mar 28, 2018 at 09:34:35PM +0800, linzhecheng wrote:
> > Check device having the feature of VIRTIO_CONSOLE_F_EMERG_WRITE before
> > get config->emerg_wr. It is neccessary because sizeof(virtio_console_config)
> > is 8 byte if VirtIOSerial doesn't have the feature of
> > VIRTIO_CONSOLE_F_EMERG_WRITE(see virtio_serial_device_realize),
> > read/write emerg_wr will lead to heap-over-flow.
> >
> > Signed-off-by: linzhecheng <linzhecheng@huawei.com>
>
> Michael or Paolo: Please merge for QEMU 2.12
>
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Will merge.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2018-03-28 13:34 [Qemu-devel] [PATCH v2] virtio-serial: fix heap-over-flow linzhecheng
2018-04-04 9:53 ` Stefan Hajnoczi
2018-04-04 14:22 ` Michael S. Tsirkin
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