[PATCH V3] vp_vdpa: fix id_table array not null terminated error

[Xiaoguang Wang <lege.wang@xxxxxxxxxxxxxxx>]

Allocate one extra virtio_device_id as null terminator, otherwise
vdpa_mgmtdev_get_classes() may iterate multiple times and visit
undefined memory.

Fixes: ffbda8e9df10 ("vdpa/vp_vdpa : add vdpa tool support in vp_vdpa")
Cc: stable@xxxxxxxxxxxxxxx
Suggested-by: Parav Pandit <parav@xxxxxxxxxx>
Signed-off-by: Angus Chen <angus.chen@xxxxxxxxxxxxxxx>
Signed-off-by: Xiaoguang Wang <lege.wang@xxxxxxxxxxxxxxx>
---
V3:
 Use array assignment style for mdev_id.
V2:
  Use kcalloc() api.
---
 drivers/vdpa/virtio_pci/vp_vdpa.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c
index ac4ab22f7d8b..16380764275e 100644
--- a/drivers/vdpa/virtio_pci/vp_vdpa.c
+++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
@@ -612,7 +612,11 @@ static int vp_vdpa_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		goto mdev_err;
 	}
 
-	mdev_id = kzalloc(sizeof(struct virtio_device_id), GFP_KERNEL);
+	/*
+	 * id_table should be a null terminated array, so allocate one additional
+	 * entry here, see vdpa_mgmtdev_get_classes().
+	 */
+	mdev_id = kcalloc(2, sizeof(struct virtio_device_id), GFP_KERNEL);
 	if (!mdev_id) {
 		err = -ENOMEM;
 		goto mdev_id_err;
@@ -632,8 +636,8 @@ static int vp_vdpa_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		goto probe_err;
 	}
 
-	mdev_id->device = mdev->id.device;
-	mdev_id->vendor = mdev->id.vendor;
+	mdev_id[0].device = mdev->id.device;
+	mdev_id[0].vendor = mdev->id.vendor;
 	mgtdev->id_table = mdev_id;
 	mgtdev->max_supported_vqs = vp_modern_get_num_queues(mdev);
 	mgtdev->supported_features = vp_modern_get_features(mdev);
-- 
2.40.1