Re: [RFC PATCH v5 04/23] hw/virtio: Replace g_memdup() by g_memdup2()

[Jason Wang]

在 2022/4/8 21:33, Eugenio Pérez 写道:
> From: Philippe Mathieu-Daudé <philmd@redhat.com>
>
> Per 
> https://discourse.gnome.org/t/port-your-module-from-g-memdup-to-g-memdup2-now/5538
>
>    The old API took the size of the memory to duplicate as a guint,
>    whereas most memory functions take memory sizes as a gsize. This
>    made it easy to accidentally pass a gsize to g_memdup(). For large
>    values, that would lead to a silent truncation of the size from 64
>    to 32 bits, and result in a heap area being returned which is
>    significantly smaller than what the caller expects. This can likely
>    be exploited in various modules to cause a heap buffer overflow.
>
> Replace g_memdup() by the safer g_memdup2() wrapper.
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---


Acked-by: Jason Wang <jasowang@redhat.com>


>   hw/net/virtio-net.c       | 3 ++-
>   hw/virtio/virtio-crypto.c | 6 +++---
>   2 files changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index 1067e72b39..e4748a7e6c 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -1443,7 +1443,8 @@ static void virtio_net_handle_ctrl(VirtIODevice *vdev, 
> VirtQueue *vq)
>           }
>   
>           iov_cnt = elem->out_num;
> -        iov2 = iov = g_memdup(elem->out_sg, sizeof(struct iovec) * 
> elem->out_num);
> +        iov2 = iov = g_memdup2(elem->out_sg,
> +                               sizeof(struct iovec) * elem->out_num);
>           s = iov_to_buf(iov, iov_cnt, 0, &ctrl, sizeof(ctrl));
>           iov_discard_front(&iov, &iov_cnt, sizeof(ctrl));
>           if (s != sizeof(ctrl)) {
> diff --git a/hw/virtio/virtio-crypto.c b/hw/virtio/virtio-crypto.c
> index dcd80b904d..0e31e3cc04 100644
> --- a/hw/virtio/virtio-crypto.c
> +++ b/hw/virtio/virtio-crypto.c
> @@ -242,7 +242,7 @@ static void virtio_crypto_handle_ctrl(VirtIODevice *vdev, 
> VirtQueue *vq)
>           }
>   
>           out_num = elem->out_num;
> -        out_iov_copy = g_memdup(elem->out_sg, sizeof(out_iov[0]) * out_num);
> +        out_iov_copy = g_memdup2(elem->out_sg, sizeof(out_iov[0]) * out_num);
>           out_iov = out_iov_copy;
>   
>           in_num = elem->in_num;
> @@ -605,11 +605,11 @@ virtio_crypto_handle_request(VirtIOCryptoReq *request)
>       }
>   
>       out_num = elem->out_num;
> -    out_iov_copy = g_memdup(elem->out_sg, sizeof(out_iov[0]) * out_num);
> +    out_iov_copy = g_memdup2(elem->out_sg, sizeof(out_iov[0]) * out_num);
>       out_iov = out_iov_copy;
>   
>       in_num = elem->in_num;
> -    in_iov_copy = g_memdup(elem->in_sg, sizeof(in_iov[0]) * in_num);
> +    in_iov_copy = g_memdup2(elem->in_sg, sizeof(in_iov[0]) * in_num);
>       in_iov = in_iov_copy;
>   
>       if (unlikely(iov_to_buf(out_iov, out_num, 0, &req, sizeof(req))