CVE-2022-48757

In the Linux kernel, the following vulnerability has been resolved:

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.