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

[Aleksandr Mishin <amishin@xxxxxxxxxx>]

Thank you! I assumed something like this, but I couldn't find any 
confirmations and offered a patch as a solution.

On 09.04.2024 14:10, Junxian Huang wrote:
> On 2024/4/9 17:26, Leon Romanovsky wrote:
> > 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
>
> Yeah, it's already checked here:
>
> 6911 static int hns_roce_hw_v2_init_instance(struct hnae3_handle *handle)
> 6912 {
> 6913         const struct hnae3_ae_ops *ops = handle->ae_algo->ops;
> 6914         const struct pci_device_id *id;
> 6915         struct device *dev = &handle->pdev->dev;
> 6916         int ret;
> 6917
> 6918         handle->rinfo.instance_state = HNS_ROCE_STATE_INIT;
> 6919
> 6920         if (ops->ae_dev_resetting(handle) || ops->get_hw_reset_stat(handle)) {
> 6921                 handle->rinfo.instance_state = HNS_ROCE_STATE_NON_INIT;
> 6922                 goto reset_chk_err;
> 6923         }
> 6924
> 6925         id = pci_match_id(hns_roce_hw_v2_pci_tbl, handle->pdev);
> 6926         if (!id)
> 6927                 return 0;
> 6928
> 6929         if (id->driver_data && handle->pdev->revision == PCI_REVISION_ID_HIP08)
> 6930                 return 0;
> 6931
> 6932         ret = __hns_roce_hw_v2_init_instance(handle);
>
> Junxian
>
> > > Found by Linux Verification Center (linuxtesting.org) with SVACE.
> > >
> > > Fixes: 0b567cde9d7a ("RDMA/hns: Enable RoCE on virtual functions")
> > > Signed-off-by: Aleksandr Mishin <amishin@xxxxxxxxxx>
> > > ---
> > >   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

--
Kind regards
Aleksandr