5.4-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ Upstream commit 90b2f49a502fa71090d9f4fe29a2f51fe5dff76d ]
ovs_vport_cmd_fill_info() can be called without RTNL or RCU.
Use RCU protection and dev_net_rcu() to avoid potential UAF.
Fixes: 9354d4520342 ("openvswitch: reliable interface indentification in port dumps") Signed-off-by: Eric Dumazet edumazet@google.com Reviewed-by: Kuniyuki Iwashima kuniyu@amazon.com Link: https://patch.msgid.link/20250207135841.1948589-6-edumazet@google.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/openvswitch/datapath.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c index 4c537e74b18c7..20a57a3dc2813 100644 --- a/net/openvswitch/datapath.c +++ b/net/openvswitch/datapath.c @@ -1912,6 +1912,7 @@ static int ovs_vport_cmd_fill_info(struct vport *vport, struct sk_buff *skb, { struct ovs_header *ovs_header; struct ovs_vport_stats vport_stats; + struct net *net_vport; int err;
ovs_header = genlmsg_put(skb, portid, seq, &dp_vport_genl_family, @@ -1928,12 +1929,15 @@ static int ovs_vport_cmd_fill_info(struct vport *vport, struct sk_buff *skb, nla_put_u32(skb, OVS_VPORT_ATTR_IFINDEX, vport->dev->ifindex)) goto nla_put_failure;
- if (!net_eq(net, dev_net(vport->dev))) { - int id = peernet2id_alloc(net, dev_net(vport->dev), gfp); + rcu_read_lock(); + net_vport = dev_net_rcu(vport->dev); + if (!net_eq(net, net_vport)) { + int id = peernet2id_alloc(net, net_vport, GFP_ATOMIC);
if (nla_put_s32(skb, OVS_VPORT_ATTR_NETNSID, id)) - goto nla_put_failure; + goto nla_put_failure_unlock; } + rcu_read_unlock();
ovs_vport_get_stats(vport, &vport_stats); if (nla_put_64bit(skb, OVS_VPORT_ATTR_STATS, @@ -1951,6 +1955,8 @@ static int ovs_vport_cmd_fill_info(struct vport *vport, struct sk_buff *skb, genlmsg_end(skb, ovs_header); return 0;
+nla_put_failure_unlock: + rcu_read_unlock(); nla_put_failure: err = -EMSGSIZE; error: