From: Longxuan Yu Date: Mon, 20 Apr 2026 03:18:46 +0000 (+0800) Subject: 8021q: delete cleared egress QoS mappings X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7dddc74af369478ba7f9bc136d0fc1dc4570cb66;p=thirdparty%2Fkernel%2Fstable.git 8021q: delete cleared egress QoS mappings vlan_dev_set_egress_priority() currently keeps cleared egress priority mappings in the hash as tombstones. Repeated set/clear cycles with distinct skb priorities therefore accumulate mapping nodes until device teardown and leak memory. Delete mappings when vlan_prio is cleared instead of keeping tombstones. Now that the egress mapping lists are RCU protected, the node can be unlinked safely and freed after a grace period. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@kernel.org Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Co-developed-by: Yuan Tan Signed-off-by: Yuan Tan Signed-off-by: Longxuan Yu Signed-off-by: Ren Wei Link: https://patch.msgid.link/ecfa6f6ce2467a42647ff4c5221238ae85b79a59.1776647968.git.yuantan098@gmail.com Signed-off-by: Paolo Abeni --- diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c index a5340932b657..7aa3af8b10ea 100644 --- a/net/8021q/vlan_dev.c +++ b/net/8021q/vlan_dev.c @@ -172,26 +172,34 @@ int vlan_dev_set_egress_priority(const struct net_device *dev, u32 skb_prio, u16 vlan_prio) { struct vlan_dev_priv *vlan = vlan_dev_priv(dev); + struct vlan_priority_tci_mapping __rcu **mpp; struct vlan_priority_tci_mapping *mp; struct vlan_priority_tci_mapping *np; u32 bucket = skb_prio & 0xF; u32 vlan_qos = (vlan_prio << VLAN_PRIO_SHIFT) & VLAN_PRIO_MASK; /* See if a priority mapping exists.. */ - mp = rtnl_dereference(vlan->egress_priority_map[bucket]); + mpp = &vlan->egress_priority_map[bucket]; + mp = rtnl_dereference(*mpp); while (mp) { if (mp->priority == skb_prio) { - if (mp->vlan_qos && !vlan_qos) + if (!vlan_qos) { + rcu_assign_pointer(*mpp, rtnl_dereference(mp->next)); vlan->nr_egress_mappings--; - else if (!mp->vlan_qos && vlan_qos) - vlan->nr_egress_mappings++; - WRITE_ONCE(mp->vlan_qos, vlan_qos); + kfree_rcu(mp, rcu); + } else { + WRITE_ONCE(mp->vlan_qos, vlan_qos); + } return 0; } - mp = rtnl_dereference(mp->next); + mpp = &mp->next; + mp = rtnl_dereference(*mpp); } /* Create a new mapping then. */ + if (!vlan_qos) + return 0; + np = kmalloc_obj(struct vlan_priority_tci_mapping); if (!np) return -ENOBUFS; diff --git a/net/8021q/vlan_netlink.c b/net/8021q/vlan_netlink.c index a5b16833e2ce..368d53ca7d87 100644 --- a/net/8021q/vlan_netlink.c +++ b/net/8021q/vlan_netlink.c @@ -263,10 +263,6 @@ static int vlan_fill_info(struct sk_buff *skb, const struct net_device *dev) for (pm = rcu_dereference_rtnl(vlan->egress_priority_map[i]); pm; pm = rcu_dereference_rtnl(pm->next)) { u16 vlan_qos = READ_ONCE(pm->vlan_qos); - - if (!vlan_qos) - continue; - m.from = pm->priority; m.to = (vlan_qos >> 13) & 0x7; if (nla_put(skb, IFLA_VLAN_QOS_MAPPING,