Re: [PATCH] scsi: mpt3sas: fix NULL pointer access in mpt3sas_transport_port_add()

["haowenchao (C)" <haowenchao2@huawei.com>]

On 2023/2/25 18:01, Wenchao Hao wrote:
> port is allocated by sas_port_alloc_num() and rphy is allocated by
> sas_end_device_alloc() or sas_expander_alloc() which may return NULL,
> so we need to check the rphy to avoid possible NULL pointer access.
> 
> If sas_rphy_add() called with failure rphy is set to NULL, we would
> access the rphy in next lines which would also result NULL pointer
> access.
> 
> Fix commit 78316e9dfc24 ("scsi: mpt3sas: Fix possible resource leaks
> in mpt3sas_transport_port_add()")
> 
> Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
> ---
>   drivers/scsi/mpt3sas/mpt3sas_transport.c | 14 ++++++++++++--
>   1 file changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/scsi/mpt3sas/mpt3sas_transport.c b/drivers/scsi/mpt3sas/mpt3sas_transport.c
> index e5ecd6ada6cd..e8a4750f6ec4 100644
> --- a/drivers/scsi/mpt3sas/mpt3sas_transport.c
> +++ b/drivers/scsi/mpt3sas/mpt3sas_transport.c
> @@ -785,7 +785,7 @@ mpt3sas_transport_port_add(struct MPT3SAS_ADAPTER *ioc, u16 handle,
>   		goto out_fail;
>   	}
>   	port = sas_port_alloc_num(sas_node->parent_dev);
> -	if ((sas_port_add(port))) {
> +	if (!port || (sas_port_add(port))) {
>   		ioc_err(ioc, "failure at %s:%d/%s()!\n",
>   			__FILE__, __LINE__, __func__);
>   		goto out_fail;
> @@ -824,6 +824,12 @@ mpt3sas_transport_port_add(struct MPT3SAS_ADAPTER *ioc, u16 handle,
>   			    mpt3sas_port->remote_identify.sas_address;
>   	}
>   
> +	if (!rphy) {
> +		ioc_err(ioc, "failure at %s:%d/%s()!\n",
> +			__FILE__, __LINE__, __func__);
> +		goto out_delete_port;
> +	}
> +
>   	rphy->identify = mpt3sas_port->remote_identify;
>   
>   	if ((sas_rphy_add(rphy))) {
> @@ -831,6 +837,7 @@ mpt3sas_transport_port_add(struct MPT3SAS_ADAPTER *ioc, u16 handle,
>   			__FILE__, __LINE__, __func__);
>   		sas_rphy_free(rphy);
>   		rphy = NULL;
> +		goto out_delete_port;
>   	}
>   
>   	if (mpt3sas_port->remote_identify.device_type == SAS_END_DEVICE) {
> @@ -857,7 +864,10 @@ mpt3sas_transport_port_add(struct MPT3SAS_ADAPTER *ioc, u16 handle,
>   		    rphy_to_expander_device(rphy), hba_port->port_id);
>   	return mpt3sas_port;
>   
> - out_fail:
> +out_delete_port:
> +	sas_port_delete(port);
> +
> +out_fail:
>   	list_for_each_entry_safe(mpt3sas_phy, next, &mpt3sas_port->phy_list,
>   	    port_siblings)
>   		list_del(&mpt3sas_phy->port_siblings);

friendly ping...