From 8f88c78d24f6f346919007cd459fd7e51a8c7779 Mon Sep 17 00:00:00 2001 From: Congyu Liu Date: Tue, 18 Jan 2022 14:20:13 -0500 Subject: net: fix information leakage in /proc/net/ptype commit 47934e06b65637c88a762d9c98329ae6e3238888 upstream. 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 Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- net/core/net-procfs.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'net/core/net-procfs.c') diff --git a/net/core/net-procfs.c b/net/core/net-procfs.c index 2bf83299600a..f284d7c5b34b 100644 --- a/net/core/net-procfs.c +++ b/net/core/net-procfs.c @@ -277,7 +277,8 @@ 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 -- cgit v1.2.3