From 9d45921ee4cb364910097e7d1b7558559c2f9fd2 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Mon, 14 Nov 2022 10:45:09 +0200 Subject: [PATCH] bridge: switchdev: Fix memory leaks when changing VLAN protocol 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 Tested-by: Vlad Buslov Signed-off-by: Ido Schimmel Acked-by: Nikolay Aleksandrov Link: https://lore.kernel.org/r/20221114084509.860831-1-idosch@nvidia.com Signed-off-by: Paolo Abeni --- 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 6e53dc9..9ffd40b 100644 --- a/net/bridge/br_vlan.c +++ b/net/bridge/br_vlan.c @@ -959,6 +959,8 @@ 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; @@ -973,8 +975,11 @@ 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; @@ -983,13 +988,19 @@ err_filt: 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; -- 2.7.4