Re: [PATCH v2] qed/qed_sriov: guard against NULL derefs from qed_iov_get_vf_info

[Michal Swiatkowski <michal.swiatkowski@linux.intel.com>]

On Thu, Mar 16, 2023 at 01:29:21PM +0300, Daniil Tatianin wrote:
> We have to make sure that the info returned by the helper is valid
> before using it.
> 
> Found by Linux Verification Center (linuxtesting.org) with the SVACE
> static analysis tool.
> 
> Fixes: f990c82c385b ("qed*: Add support for ndo_set_vf_trust")
> Fixes: 733def6a04bf ("qed*: IOV link control")
> Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
> ---
> Changes since v1:
> - Add a vf check to qed_iov_handle_trust_change as well
> ---
>  drivers/net/ethernet/qlogic/qed/qed_sriov.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/qlogic/qed/qed_sriov.c b/drivers/net/ethernet/qlogic/qed/qed_sriov.c
> index 2bf18748581d..fa167b1aa019 100644
> --- a/drivers/net/ethernet/qlogic/qed/qed_sriov.c
> +++ b/drivers/net/ethernet/qlogic/qed/qed_sriov.c
> @@ -4404,6 +4404,9 @@ qed_iov_configure_min_tx_rate(struct qed_dev *cdev, int vfid, u32 rate)
>  	}
>  
>  	vf = qed_iov_get_vf_info(QED_LEADING_HWFN(cdev), (u16)vfid, true);
> +	if (!vf)
> +		return -EINVAL;
> +
>  	vport_id = vf->vport_id;
>  
>  	return qed_configure_vport_wfq(cdev, vport_id, rate);
> @@ -5152,7 +5155,7 @@ static void qed_iov_handle_trust_change(struct qed_hwfn *hwfn)
>  
>  		/* Validate that the VF has a configured vport */
>  		vf = qed_iov_get_vf_info(hwfn, i, true);
> -		if (!vf->vport_instance)
> +		if (!vf || !vf->vport_instance)
>  			continue;
>  
>  		memset(&params, 0, sizeof(params));
> -- 
> 2.25.1
> 

Thanks,
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>