From: Xie Yongji xieyongji@bytedance.com
stable inclusion from stable-5.10.52 commit f6ec306b93dc600a0ab3bb2693568ef1cc5f7f7a bugzilla: 175542 https://gitee.com/openeuler/kernel/issues/I4DTKU
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ 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 Signed-off-by: Chen Jun chenjun102@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com Signed-off-by: Chen Jun chenjun102@huawei.com --- 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 1836cc56e357..673522874cec 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; } @@ -1712,7 +1712,7 @@ 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);