Merge branch 'net-vlan-fix-vlan-0-refcount-imbalance-of-toggling-filtering-during-runtime'

Dong Chenchen says:

====================
net: vlan: fix VLAN 0 refcount imbalance of toggling filtering during runtime

Fix VLAN 0 refcount imbalance of toggling filtering during runtime.
====================

Link: https://patch.msgid.link/20250716034504.2285203-1-dongchenchen2@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 120 insertions, 21 deletions

diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index 06908e37c3d9..9a6df8c1daf9 100644
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -357,6 +357,35 @@ static int __vlan_device_event(struct net_device *dev, unsigned long event)
 	return err;
 }
 
+static void vlan_vid0_add(struct net_device *dev)
+{
+	struct vlan_info *vlan_info;
+	int err;
+
+	if (!(dev->features & NETIF_F_HW_VLAN_CTAG_FILTER))
+		return;
+
+	pr_info("adding VLAN 0 to HW filter on device %s\n", dev->name);
+
+	err = vlan_vid_add(dev, htons(ETH_P_8021Q), 0);
+	if (err)
+		return;
+
+	vlan_info = rtnl_dereference(dev->vlan_info);
+	vlan_info->auto_vid0 = true;
+}
+
+static void vlan_vid0_del(struct net_device *dev)
+{
+	struct vlan_info *vlan_info = rtnl_dereference(dev->vlan_info);
+
+	if (!vlan_info || !vlan_info->auto_vid0)
+		return;
+
+	vlan_info->auto_vid0 = false;
+	vlan_vid_del(dev, htons(ETH_P_8021Q), 0);
+}
+
 static int vlan_device_event(struct notifier_block *unused, unsigned long event,
 			     void *ptr)
 {
@@ -378,15 +407,10 @@ static int vlan_device_event(struct notifier_block *unused, unsigned long event,
 			return notifier_from_errno(err);
 	}
 
-	if ((event == NETDEV_UP) &&
-	    (dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)) {
-		pr_info("adding VLAN 0 to HW filter on device %s\n",
-			dev->name);
-		vlan_vid_add(dev, htons(ETH_P_8021Q), 0);
-	}
-	if (event == NETDEV_DOWN &&
-	    (dev->features & NETIF_F_HW_VLAN_CTAG_FILTER))
-		vlan_vid_del(dev, htons(ETH_P_8021Q), 0);
+	if (event == NETDEV_UP)
+		vlan_vid0_add(dev);
+	else if (event == NETDEV_DOWN)
+		vlan_vid0_del(dev);
 
 	vlan_info = rtnl_dereference(dev->vlan_info);
 	if (!vlan_info)
diff --git a/net/8021q/vlan.h b/net/8021q/vlan.h
index 5eaf38875554..c7ffe591d593 100644
--- a/net/8021q/vlan.h
+++ b/net/8021q/vlan.h
@@ -33,6 +33,7 @@ struct vlan_info {
 	struct vlan_group	grp;
 	struct list_head	vid_list;
 	unsigned int		nr_vids;
+	bool			auto_vid0;
 	struct rcu_head		rcu;
 };
 
diff --git a/tools/testing/selftests/net/vlan_hw_filter.sh b/tools/testing/selftests/net/vlan_hw_filter.sh
index 7bc804ffaf7c..0fb56baf28e4 100755
--- a/tools/testing/selftests/net/vlan_hw_filter.sh
+++ b/tools/testing/selftests/net/vlan_hw_filter.sh
@@ -3,27 +3,101 @@
 
 readonly NETNS="ns-$(mktemp -u XXXXXX)"
 
+ALL_TESTS="
+	test_vlan_filter_check
+	test_vlan0_del_crash_01
+	test_vlan0_del_crash_02
+	test_vlan0_del_crash_03
+	test_vid0_memleak
+"
+
 ret=0
 
+setup() {
+	ip netns add ${NETNS}
+}
+
 cleanup() {
-	ip netns del $NETNS
+	ip netns del $NETNS 2>/dev/null
 }
 
 trap cleanup EXIT
 
 fail() {
-    echo "ERROR: ${1:-unexpected return code} (ret: $_)" >&2
-    ret=1
+	echo "ERROR: ${1:-unexpected return code} (ret: $_)" >&2
+	ret=1
+}
+
+tests_run()
+{
+	local current_test
+	for current_test in ${TESTS:-$ALL_TESTS}; do
+		$current_test
+	done
+}
+
+test_vlan_filter_check() {
+	setup
+	ip netns exec ${NETNS} ip link add bond0 type bond mode 0
+	ip netns exec ${NETNS} ip link add bond_slave_1 type veth peer veth2
+	ip netns exec ${NETNS} ip link set bond_slave_1 master bond0
+	ip netns exec ${NETNS} ethtool -K bond0 rx-vlan-filter off
+	ip netns exec ${NETNS} ip link add link bond_slave_1 name bond_slave_1.0 type vlan id 0
+	ip netns exec ${NETNS} ip link add link bond0 name bond0.0 type vlan id 0
+	ip netns exec ${NETNS} ip link set bond_slave_1 nomaster
+	ip netns exec ${NETNS} ip link del veth2 || fail "Please check vlan HW filter function"
+	cleanup
 }
 
-ip netns add ${NETNS}
-ip netns exec ${NETNS} ip link add bond0 type bond mode 0
-ip netns exec ${NETNS} ip link add bond_slave_1 type veth peer veth2
-ip netns exec ${NETNS} ip link set bond_slave_1 master bond0
-ip netns exec ${NETNS} ethtool -K bond0 rx-vlan-filter off
-ip netns exec ${NETNS} ip link add link bond_slave_1 name bond_slave_1.0 type vlan id 0
-ip netns exec ${NETNS} ip link add link bond0 name bond0.0 type vlan id 0
-ip netns exec ${NETNS} ip link set bond_slave_1 nomaster
-ip netns exec ${NETNS} ip link del veth2 || fail "Please check vlan HW filter function"
+#enable vlan_filter feature of real_dev with vlan0 during running time
+test_vlan0_del_crash_01() {
+	setup
+	ip netns exec ${NETNS} ip link add bond0 type bond mode 0
+	ip netns exec ${NETNS} ip link add link bond0 name vlan0 type vlan id 0 protocol 802.1q
+	ip netns exec ${NETNS} ethtool -K bond0 rx-vlan-filter off
+	ip netns exec ${NETNS} ifconfig bond0 up
+	ip netns exec ${NETNS} ethtool -K bond0 rx-vlan-filter on
+	ip netns exec ${NETNS} ifconfig bond0 down
+	ip netns exec ${NETNS} ifconfig bond0 up
+	ip netns exec ${NETNS} ip link del vlan0 || fail "Please check vlan HW filter function"
+	cleanup
+}
+
+#enable vlan_filter feature and add vlan0 for real_dev during running time
+test_vlan0_del_crash_02() {
+	setup
+	ip netns exec ${NETNS} ip link add bond0 type bond mode 0
+	ip netns exec ${NETNS} ethtool -K bond0 rx-vlan-filter off
+	ip netns exec ${NETNS} ifconfig bond0 up
+	ip netns exec ${NETNS} ethtool -K bond0 rx-vlan-filter on
+	ip netns exec ${NETNS} ip link add link bond0 name vlan0 type vlan id 0 protocol 802.1q
+	ip netns exec ${NETNS} ifconfig bond0 down
+	ip netns exec ${NETNS} ifconfig bond0 up
+	ip netns exec ${NETNS} ip link del vlan0 || fail "Please check vlan HW filter function"
+	cleanup
+}
+
+#enable vlan_filter feature of real_dev during running time
+#test kernel_bug of vlan unregister
+test_vlan0_del_crash_03() {
+	setup
+	ip netns exec ${NETNS} ip link add bond0 type bond mode 0
+	ip netns exec ${NETNS} ip link add link bond0 name vlan0 type vlan id 0 protocol 802.1q
+	ip netns exec ${NETNS} ethtool -K bond0 rx-vlan-filter off
+	ip netns exec ${NETNS} ifconfig bond0 up
+	ip netns exec ${NETNS} ethtool -K bond0 rx-vlan-filter on
+	ip netns exec ${NETNS} ifconfig bond0 down
+	ip netns exec ${NETNS} ip link del vlan0 || fail "Please check vlan HW filter function"
+	cleanup
+}
+
+test_vid0_memleak() {
+	setup
+	ip netns exec ${NETNS} ip link add bond0 up type bond mode 0
+	ip netns exec ${NETNS} ethtool -K bond0 rx-vlan-filter off
+	ip netns exec ${NETNS} ip link del dev bond0 || fail "Please check vlan HW filter function"
+	cleanup
+}
 
+tests_run
 exit $ret