Re: [PATCH] RDMA: hns: Fix possible null pointer dereference

[Leon Romanovsky <leon@kernel.org>]

On Tue, Apr 09, 2024 at 11:30:47AM +0300, Aleksandr Mishin wrote:
> In hns_roce_hw_v2_get_cfg() pci_match_id() may return
> NULL which is later dereferenced. Fix this bug by adding NULL check.

I don't know, this NULL can't happen in this flow.

Thanks

> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Fixes: 0b567cde9d7a ("RDMA/hns: Enable RoCE on virtual functions")
> Signed-off-by: Aleksandr Mishin <amishin@t-argos.ru>
> ---
>  drivers/infiniband/hw/hns/hns_roce_hw_v2.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
> index ba7ae792d279..31a2093334d9 100644
> --- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
> +++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
> @@ -6754,7 +6754,7 @@ static const struct pci_device_id hns_roce_hw_v2_pci_tbl[] = {
>  
>  MODULE_DEVICE_TABLE(pci, hns_roce_hw_v2_pci_tbl);
>  
> -static void hns_roce_hw_v2_get_cfg(struct hns_roce_dev *hr_dev,
> +static int hns_roce_hw_v2_get_cfg(struct hns_roce_dev *hr_dev,
>  				  struct hnae3_handle *handle)
>  {
>  	struct hns_roce_v2_priv *priv = hr_dev->priv;
> @@ -6763,6 +6763,9 @@ static void hns_roce_hw_v2_get_cfg(struct hns_roce_dev *hr_dev,
>  
>  	hr_dev->pci_dev = handle->pdev;
>  	id = pci_match_id(hns_roce_hw_v2_pci_tbl, hr_dev->pci_dev);
> +	if (!id)
> +		return -ENXIO;
> +
>  	hr_dev->is_vf = id->driver_data;
>  	hr_dev->dev = &handle->pdev->dev;
>  	hr_dev->hw = &hns_roce_hw_v2;
> @@ -6789,6 +6792,8 @@ static void hns_roce_hw_v2_get_cfg(struct hns_roce_dev *hr_dev,
>  
>  	hr_dev->reset_cnt = handle->ae_algo->ops->ae_dev_reset_cnt(handle);
>  	priv->handle = handle;
> +
> +	return 0;
>  }
>  
>  static int __hns_roce_hw_v2_init_instance(struct hnae3_handle *handle)
> @@ -6806,7 +6811,11 @@ static int __hns_roce_hw_v2_init_instance(struct hnae3_handle *handle)
>  		goto error_failed_kzalloc;
>  	}
>  
> -	hns_roce_hw_v2_get_cfg(hr_dev, handle);
> +	ret = hns_roce_hw_v2_get_cfg(hr_dev, handle);
> +	if (ret) {
> +		dev_err(hr_dev->dev, "RoCE Engine cfg failed!\n");
> +		goto error_failed_roce_init;
> +	}
>  
>  	ret = hns_roce_init(hr_dev);
>  	if (ret) {
> -- 
> 2.30.2
>