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

[Aleksandr Mishin]

In hns_roce_hw_v2_get_cfg() pci_match_id() may return
NULL which is later dereferenced. Fix this bug by adding NULL check.

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