> From: Xiaoguang Wang <lege.wang@xxxxxxxxxxxxxxx>
> Sent: Thursday, October 31, 2024 9:35 AM
>
> Allocate one extra virtio_device_id as null terminator, otherwise
> vdpa_mgmtdev_get_classes() may iterate multiple times and visit undefined
> memory.
>
> Fixes: ffbda8e9df10 ("vdpa/vp_vdpa : add vdpa tool support in vp_vdpa")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Xiaoguang Wang <lege.wang@xxxxxxxxxxxxxxx>
> ---
> drivers/vdpa/virtio_pci/vp_vdpa.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c
> b/drivers/vdpa/virtio_pci/vp_vdpa.c
> index ac4ab22f7d8b..74cc4ed77cc4 100644
> --- a/drivers/vdpa/virtio_pci/vp_vdpa.c
> +++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
> @@ -612,7 +612,11 @@ static int vp_vdpa_probe(struct pci_dev *pdev,
> const struct pci_device_id *id)
> goto mdev_err;
> }
>
> - mdev_id = kzalloc(sizeof(struct virtio_device_id), GFP_KERNEL);
> + /*
> + * id_table should be a null terminated array.
> + * See vdpa_mgmtdev_get_classes().
> + */
> + mdev_id = kzalloc(sizeof(struct virtio_device_id) * 2, GFP_KERNEL);
Only one additional entry is needed for null termination. No need to allocate 2x memory.
Even though you have only two entries. Reading code as +1 is better to understand null termination.
And for array, you should use,
array = kcalloc(2, sizeof(mdev_id), GFP_KERNEL);
> if (!mdev_id) {
> err = -ENOMEM;
> goto mdev_id_err;
> --
> 2.40.1
>
