diff options
| author | Congyu Liu | 2022-01-18 14:20:13 -0500 |
|---|---|---|
| committer | David S. Miller | 2022-01-20 10:12:53 +0000 |
| commit | 47934e06b65637c88a762d9c98329ae6e3238888 (patch) | |
| tree | aec48cf65cd8abc38011c80707316a5d94e0ea16 | |
| parent | fa2e1ba3e9e39072fa7a6a9d11ac432c505b4ac7 (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 <liu3101@purdue.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/linux/netdevice.h | 1 | ||||
| -rw-r--r-- | net/core/net-procfs.c | 3 | ||||
| -rw-r--r-- | net/packet/af_packet.c | 2 |
3 files changed, 5 insertions, 1 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 3213c7227b59..e490b84732d1 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2548,6 +2548,7 @@ struct packet_type { struct net_device *); bool (*id_match)(struct packet_type *ptype, struct sock *sk); + struct net *af_packet_net; void *af_packet_priv; struct list_head list; }; diff --git a/net/core/net-procfs.c b/net/core/net-procfs.c index d8b9dbabd4a4..5b8016335aca 100644 --- a/net/core/net-procfs.c +++ b/net/core/net-procfs.c @@ -260,7 +260,8 @@ static int ptype_seq_show(struct seq_file *seq, void *v) if (v == SEQ_START_TOKEN) seq_puts(seq, "Type Device Function\n"); - else if (pt->dev == NULL || dev_net(pt->dev) == seq_file_net(seq)) { + else if ((!pt->af_packet_net || net_eq(pt->af_packet_net, seq_file_net(seq))) && + (!pt->dev || net_eq(dev_net(pt->dev), seq_file_net(seq)))) { if (pt->type == htons(ETH_P_ALL)) seq_puts(seq, "ALL "); else 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->prot_hook.dev = po->prot_hook.dev; 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; |