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authorXie Yongji <xieyongji@bytedance.com>2021-05-25 15:56:22 +0300
committerMichael S. Tsirkin <mst@redhat.com>2021-07-03 11:50:53 +0300
commitd00d8da5869a2608e97cfede094dfc5e11462a46 (patch)
treeb071750d7d5522c76cbb838c801ac614217d9480 /drivers/char
parent63947b3434f475418b9677a393d025c0962c2cf8 (diff)
downloadlinux-d00d8da5869a2608e97cfede094dfc5e11462a46.tar.xz
virtio_console: Assure used length from device is limited
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>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/virtio_console.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 59dfd9c421a1..7eaf303a7a86 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -475,7 +475,7 @@ 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;
}
@@ -1709,7 +1709,7 @@ 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);