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authorEric Dumazet <edumazet@google.com>2025-02-07 13:58:37 +0000
committerJakub Kicinski <kuba@kernel.org>2025-02-10 18:09:09 -0800
commit90b2f49a502fa71090d9f4fe29a2f51fe5dff76d (patch)
treedc514d081d83919b3793301d2ed2fc28f0fd9b2e
parenta42b69f692165ec39db42d595f4f65a4c8f42e44 (diff)
openvswitch: use RCU protection in ovs_vport_cmd_fill_info()
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>
-rw-r--r--net/openvswitch/datapath.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 225f6048867f..5d548eda742d 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -2101,6 +2101,7 @@ 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,
@@ -2117,12 +2118,15 @@ 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,
@@ -2143,6 +2147,8 @@ 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: