From 69e766612c4bcb79e19cebed9eed61d4222c1d47 Mon Sep 17 00:00:00 2001 From: Jiri Benc Date: Sun, 2 Jul 2017 19:00:57 +0200 Subject: [PATCH] vxlan: fix hlist corruption It's not a good idea to add the same hlist_node to two different hash lists. This leads to various hard to debug memory corruptions. Fixes: b1be00a6c39f ("vxlan: support both IPv4 and IPv6 sockets in a single vxlan device") Signed-off-by: Jiri Benc Signed-off-by: David S. Miller --- drivers/net/vxlan.c | 32 +++++++++++++++++++++----------- include/net/vxlan.h | 10 +++++++++- 2 files changed, 30 insertions(+), 12 deletions(-) diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 47d6e65851aa..b04e103350fb 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -229,25 +229,25 @@ static struct vxlan_sock *vxlan_find_sock(struct net *net, sa_family_t family, static struct vxlan_dev *vxlan_vs_find_vni(struct vxlan_sock *vs, int ifindex, __be32 vni) { - struct vxlan_dev *vxlan; + struct vxlan_dev_node *node; /* For flow based devices, map all packets to VNI 0 */ if (vs->flags & VXLAN_F_COLLECT_METADATA) vni = 0; - hlist_for_each_entry_rcu(vxlan, vni_head(vs, vni), hlist) { - if (vxlan->default_dst.remote_vni != vni) + hlist_for_each_entry_rcu(node, vni_head(vs, vni), hlist) { + if (node->vxlan->default_dst.remote_vni != vni) continue; if (IS_ENABLED(CONFIG_IPV6)) { - const struct vxlan_config *cfg = &vxlan->cfg; + const struct vxlan_config *cfg = &node->vxlan->cfg; if ((cfg->flags & VXLAN_F_IPV6_LINKLOCAL) && cfg->remote_ifindex != ifindex) continue; } - return vxlan; + return node->vxlan; } return NULL; @@ -2387,17 +2387,22 @@ static void vxlan_vs_del_dev(struct vxlan_dev *vxlan) struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id); spin_lock(&vn->sock_lock); - hlist_del_init_rcu(&vxlan->hlist); + hlist_del_init_rcu(&vxlan->hlist4.hlist); +#if IS_ENABLED(CONFIG_IPV6) + hlist_del_init_rcu(&vxlan->hlist6.hlist); +#endif spin_unlock(&vn->sock_lock); } -static void vxlan_vs_add_dev(struct vxlan_sock *vs, struct vxlan_dev *vxlan) +static void vxlan_vs_add_dev(struct vxlan_sock *vs, struct vxlan_dev *vxlan, + struct vxlan_dev_node *node) { struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id); __be32 vni = vxlan->default_dst.remote_vni; + node->vxlan = vxlan; spin_lock(&vn->sock_lock); - hlist_add_head_rcu(&vxlan->hlist, vni_head(vs, vni)); + hlist_add_head_rcu(&node->hlist, vni_head(vs, vni)); spin_unlock(&vn->sock_lock); } @@ -2849,6 +2854,7 @@ static int __vxlan_sock_add(struct vxlan_dev *vxlan, bool ipv6) { struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id); struct vxlan_sock *vs = NULL; + struct vxlan_dev_node *node; if (!vxlan->cfg.no_share) { spin_lock(&vn->sock_lock); @@ -2866,12 +2872,16 @@ static int __vxlan_sock_add(struct vxlan_dev *vxlan, bool ipv6) if (IS_ERR(vs)) return PTR_ERR(vs); #if IS_ENABLED(CONFIG_IPV6) - if (ipv6) + if (ipv6) { rcu_assign_pointer(vxlan->vn6_sock, vs); - else + node = &vxlan->hlist6; + } else #endif + { rcu_assign_pointer(vxlan->vn4_sock, vs); - vxlan_vs_add_dev(vs, vxlan); + node = &vxlan->hlist4; + } + vxlan_vs_add_dev(vs, vxlan, node); return 0; } diff --git a/include/net/vxlan.h b/include/net/vxlan.h index b816a0a6686e..326e8498b10e 100644 --- a/include/net/vxlan.h +++ b/include/net/vxlan.h @@ -221,9 +221,17 @@ struct vxlan_config { bool no_share; }; +struct vxlan_dev_node { + struct hlist_node hlist; + struct vxlan_dev *vxlan; +}; + /* Pseudo network device */ struct vxlan_dev { - struct hlist_node hlist; /* vni hash table */ + struct vxlan_dev_node hlist4; /* vni hash table for IPv4 socket */ +#if IS_ENABLED(CONFIG_IPV6) + struct vxlan_dev_node hlist6; /* vni hash table for IPv6 socket */ +#endif struct list_head next; /* vxlan's per namespace list */ struct vxlan_sock __rcu *vn4_sock; /* listening socket for IPv4 */ #if IS_ENABLED(CONFIG_IPV6) -- 2.30.2