Re: [PATCH] qed/qed_sriov: avoid a possible NULL deref in configure_min_tx_rate

[Michal Swiatkowski]

On Wed, Mar 15, 2023 at 10:48:09PM +0300, Daniil Tatianin wrote:
> We have to make sure that the info returned by qed_iov_get_vf_info is
> valid before using it.
> 
> Found by Linux Verification Center (linuxtesting.org) with the SVACE
> static analysis tool.
> 
> Fixes: 733def6a04bf ("qed*: IOV link control")
> Signed-off-by: Daniil Tatianin <d-tatianin@xxxxxxxxxxxxxx>
> ---
>  drivers/net/ethernet/qlogic/qed/qed_sriov.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/net/ethernet/qlogic/qed/qed_sriov.c b/drivers/net/ethernet/qlogic/qed/qed_sriov.c
> index 2bf18748581d..cd43f1b23eb1 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);
> -- 
> 2.25.1
> 

There is also potential NULL pointer dereference in:
qed_iov_handle_trust_change()
Should be:
if (!vf || !vf->vf->vport_instance)

I think it can be a part of this fix.

Thanks,
Michal