From: Ido Schimmel idosch@nvidia.com
[ Upstream commit 9d45921ee4cb364910097e7d1b7558559c2f9fd2 ]
The bridge driver can offload VLANs to the underlying hardware either via switchdev or the 8021q driver. When the former is used, the VLAN is marked in the bridge driver with the 'BR_VLFLAG_ADDED_BY_SWITCHDEV' private flag.
To avoid the memory leaks mentioned in the cited commit, the bridge driver will try to delete a VLAN via the 8021q driver if the VLAN is not marked with the previously mentioned flag.
When the VLAN protocol of the bridge changes, switchdev drivers are notified via the 'SWITCHDEV_ATTR_ID_BRIDGE_VLAN_PROTOCOL' attribute, but the 8021q driver is also called to add the existing VLANs with the new protocol and delete them with the old protocol.
In case the VLANs were offloaded via switchdev, the above behavior is both redundant and buggy. Redundant because the VLANs are already programmed in hardware and drivers that support VLAN protocol change (currently only mlx5) change the protocol upon the switchdev attribute notification. Buggy because the 8021q driver is called despite these VLANs being marked with 'BR_VLFLAG_ADDED_BY_SWITCHDEV'. This leads to memory leaks [1] when the VLANs are deleted.
Fix by not calling the 8021q driver for VLANs that were already programmed via switchdev.
[1] unreferenced object 0xffff8881f6771200 (size 256): comm "ip", pid 446855, jiffies 4298238841 (age 55.240s) hex dump (first 32 bytes): 00 00 7f 0e 83 88 ff ff 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000012819ac>] vlan_vid_add+0x437/0x750 [<00000000f2281fad>] __br_vlan_set_proto+0x289/0x920 [<000000000632b56f>] br_changelink+0x3d6/0x13f0 [<0000000089d25f04>] __rtnl_newlink+0x8ae/0x14c0 [<00000000f6276baf>] rtnl_newlink+0x5f/0x90 [<00000000746dc902>] rtnetlink_rcv_msg+0x336/0xa00 [<000000001c2241c0>] netlink_rcv_skb+0x11d/0x340 [<0000000010588814>] netlink_unicast+0x438/0x710 [<00000000e1a4cd5c>] netlink_sendmsg+0x788/0xc40 [<00000000e8992d4e>] sock_sendmsg+0xb0/0xe0 [<00000000621b8f91>] ____sys_sendmsg+0x4ff/0x6d0 [<000000000ea26996>] ___sys_sendmsg+0x12e/0x1b0 [<00000000684f7e25>] __sys_sendmsg+0xab/0x130 [<000000004538b104>] do_syscall_64+0x3d/0x90 [<0000000091ed9678>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
Fixes: 279737939a81 ("net: bridge: Fix VLANs memory leak") Reported-by: Vlad Buslov vladbu@nvidia.com Tested-by: Vlad Buslov vladbu@nvidia.com Signed-off-by: Ido Schimmel idosch@nvidia.com Acked-by: Nikolay Aleksandrov razor@blackwall.org Link: https://lore.kernel.org/r/20221114084509.860831-1-idosch@nvidia.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/bridge/br_vlan.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-)
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c index 10e63ea6a13e..86441ff78a0f 100644 --- a/net/bridge/br_vlan.c +++ b/net/bridge/br_vlan.c @@ -904,6 +904,8 @@ int __br_vlan_set_proto(struct net_bridge *br, __be16 proto, list_for_each_entry(p, &br->port_list, list) { vg = nbp_vlan_group(p); list_for_each_entry(vlan, &vg->vlan_list, vlist) { + if (vlan->priv_flags & BR_VLFLAG_ADDED_BY_SWITCHDEV) + continue; err = vlan_vid_add(p->dev, proto, vlan->vid); if (err) goto err_filt; @@ -918,8 +920,11 @@ int __br_vlan_set_proto(struct net_bridge *br, __be16 proto, /* Delete VLANs for the old proto from the device filter. */ list_for_each_entry(p, &br->port_list, list) { vg = nbp_vlan_group(p); - list_for_each_entry(vlan, &vg->vlan_list, vlist) + list_for_each_entry(vlan, &vg->vlan_list, vlist) { + if (vlan->priv_flags & BR_VLFLAG_ADDED_BY_SWITCHDEV) + continue; vlan_vid_del(p->dev, oldproto, vlan->vid); + } }
return 0; @@ -928,13 +933,19 @@ int __br_vlan_set_proto(struct net_bridge *br, __be16 proto, attr.u.vlan_protocol = ntohs(oldproto); switchdev_port_attr_set(br->dev, &attr, NULL);
- list_for_each_entry_continue_reverse(vlan, &vg->vlan_list, vlist) + list_for_each_entry_continue_reverse(vlan, &vg->vlan_list, vlist) { + if (vlan->priv_flags & BR_VLFLAG_ADDED_BY_SWITCHDEV) + continue; vlan_vid_del(p->dev, proto, vlan->vid); + }
list_for_each_entry_continue_reverse(p, &br->port_list, list) { vg = nbp_vlan_group(p); - list_for_each_entry(vlan, &vg->vlan_list, vlist) + list_for_each_entry(vlan, &vg->vlan_list, vlist) { + if (vlan->priv_flags & BR_VLFLAG_ADDED_BY_SWITCHDEV) + continue; vlan_vid_del(p->dev, proto, vlan->vid); + } }
return err;