path: root/net/packet/af_packet.c
diff options
authorCongyu Liu <>2022-01-18 14:20:13 -0500
committerDavid S. Miller <>2022-01-20 10:12:53 +0000
commit47934e06b65637c88a762d9c98329ae6e3238888 (patch)
treeaec48cf65cd8abc38011c80707316a5d94e0ea16 /net/packet/af_packet.c
parentfa2e1ba3e9e39072fa7a6a9d11ac432c505b4ac7 (diff)
net: fix information leakage in /proc/net/ptype
In one net namespace, after creating a packet socket without binding it to a device, users in other net namespaces can observe the new `packet_type` added by this packet socket by reading `/proc/net/ptype` file. This is minor information leakage as packet socket is namespace aware. Add a net pointer in `packet_type` to keep the net namespace of of corresponding packet socket. In `ptype_seq_show`, this net pointer must be checked when it is not NULL. Fixes: 2feb27dbe00c ("[NETNS]: Minor information leak via /proc/net/ptype file.") Signed-off-by: Congyu Liu <> Signed-off-by: David S. Miller <>
Diffstat (limited to 'net/packet/af_packet.c')
1 files changed, 2 insertions, 0 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 5bd409ab4cc2..85ea7ddb48db 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1774,6 +1774,7 @@ static int fanout_add(struct sock *sk, struct fanout_args *args)
match-> = po->;
match->prot_hook.func = packet_rcv_fanout;
match->prot_hook.af_packet_priv = match;
+ match->prot_hook.af_packet_net = read_pnet(&match->net);
match->prot_hook.id_match = match_fanout_group;
match->max_num_members = args->max_num_members;
list_add(&match->list, &fanout_list);
@@ -3353,6 +3354,7 @@ static int packet_create(struct net *net, struct socket *sock, int protocol,
po->prot_hook.func = packet_rcv_spkt;
po->prot_hook.af_packet_priv = sk;
+ po->prot_hook.af_packet_net = sock_net(sk);
if (proto) {
po->prot_hook.type = proto;