From: Xie Yongji xieyongji@bytedance.com
[ Upstream commit d00d8da5869a2608e97cfede094dfc5e11462a46 ]
The buf->len might come from an untrusted device. This ensures the value would not exceed the size of the buffer to avoid data corruption or loss.
Signed-off-by: Xie Yongji xieyongji@bytedance.com Acked-by: Jason Wang jasowang@redhat.com Link: https://lore.kernel.org/r/20210525125622.1203-1-xieyongji@bytedance.com Signed-off-by: Michael S. Tsirkin mst@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/char/virtio_console.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 4ec08c7a7b65..2632b0fdb1b5 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -492,7 +492,7 @@ static struct port_buffer *get_inbuf(struct port *port)
buf = virtqueue_get_buf(port->in_vq, &len); if (buf) { - buf->len = len; + buf->len = min_t(size_t, len, buf->size); buf->offset = 0; port->stats.bytes_received += len; } @@ -1758,7 +1758,7 @@ static void control_work_handler(struct work_struct *work) while ((buf = virtqueue_get_buf(vq, &len))) { spin_unlock(&portdev->c_ivq_lock);
- buf->len = len; + buf->len = min_t(size_t, len, buf->size); buf->offset = 0;
handle_control_message(vq->vdev, portdev, buf);