[PATCH 4.14 15/30] ethernet: sun: add check for the mdesc_grab() - Greg Kroah-Hartman

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	patches@lists.linux.dev, Liang He <windhl@126.com>,
	Piotr Raczynski <piotr.raczynski@intel.com>,
	"David S. Miller" <davem@davemloft.net>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.14 15/30] ethernet: sun: add check for the mdesc_grab()
Date: Mon, 20 Mar 2023 15:54:39 +0100	[thread overview]
Message-ID: <20230320145420.782489249@linuxfoundation.org> (raw)
In-Reply-To: <20230320145420.204894191@linuxfoundation.org>

From: Liang He <windhl@126.com>

[ Upstream commit 90de546d9a0b3c771667af18bb3f80567eabb89b ]

In vnet_port_probe() and vsw_port_probe(), we should
check the return value of mdesc_grab() as it may
return NULL which can caused NPD bugs.

Fixes: 5d01fa0c6bd8 ("ldmvsw: Add ldmvsw.c driver code")
Fixes: 43fdf27470b2 ("[SPARC64]: Abstract out mdesc accesses for better MD update handling.")
Signed-off-by: Liang He <windhl@126.com>
Reviewed-by: Piotr Raczynski <piotr.raczynski@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/sun/ldmvsw.c  | 3 +++
 drivers/net/ethernet/sun/sunvnet.c | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/sun/ldmvsw.c b/drivers/net/ethernet/sun/ldmvsw.c
index e6b96c2989b22..f0a8e3598057e 100644
--- a/drivers/net/ethernet/sun/ldmvsw.c
+++ b/drivers/net/ethernet/sun/ldmvsw.c
@@ -289,6 +289,9 @@ static int vsw_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 
 	hp = mdesc_grab();
 
+	if (!hp)
+		return -ENODEV;
+
 	rmac = mdesc_get_property(hp, vdev->mp, remote_macaddr_prop, &len);
 	err = -ENODEV;
 	if (!rmac) {
diff --git a/drivers/net/ethernet/sun/sunvnet.c b/drivers/net/ethernet/sun/sunvnet.c
index 02ebbe74d93de..824f5951ad507 100644
--- a/drivers/net/ethernet/sun/sunvnet.c
+++ b/drivers/net/ethernet/sun/sunvnet.c
@@ -430,6 +430,9 @@ static int vnet_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 
 	hp = mdesc_grab();
 
+	if (!hp)
+		return -ENODEV;
+
 	vp = vnet_find_parent(hp, vdev->mp, vdev);
 	if (IS_ERR(vp)) {
 		pr_err("Cannot find port parent vnet\n");
-- 
2.39.2



