Revert "vlan: Fix VLAN 0 memory leak"

This reverts commit 718cb09aaa6fa78cc8124e9517efbc6c92665384.

The commit triggers multiple syzbot issues, probably due to possibility of
manually creating VLAN 0 on netdevice which will cause the code to delete
it since it can't distinguish such VLAN from implicit VLAN 0 automatically
created for devices with NETIF_F_HW_VLAN_CTAG_FILTER feature.

Reported-by: syzbot+662f783a5cdf3add2719@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/00000000000090196d0602a6167d@google.com/
Reported-by: syzbot+4b4f06495414e92701d5@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/00000000000096ae870602a61602@google.com/
Reported-by: syzbot+d810d3cd45ed1848c3f7@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/0000000000009f0f9c0602a616ce@google.com/
Fixes: 718cb09aaa6f ("vlan: Fix VLAN 0 memory leak")
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index b366211..e40aa3e 100644 (file)
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -384,7 +384,8 @@ static int vlan_device_event(struct notifier_block *unused, unsigned long event,
                        dev->name);
                vlan_vid_add(dev, htons(ETH_P_8021Q), 0);
        }
-       if (event == NETDEV_DOWN)
+       if (event == NETDEV_DOWN &&
+           (dev->features & NETIF_F_HW_VLAN_CTAG_FILTER))
                vlan_vid_del(dev, htons(ETH_P_8021Q), 0);
 
        vlan_info = rtnl_dereference(dev->vlan_info);