Description

In the Linux kernel, the following vulnerability has been resolved: bareudp: fix NULL pointer dereference in bareudp_fill_metadata_dst() bareudp_fill_metadata_dst() passes bareudp->sock to udp_tunnel6_dst_lookup() in the IPv6 path without a NULL check. The socket is only created in bareudp_open() and NULLed in bareudp_stop(), so calling this function while the device is down triggers a NULL dereference via sock->sk. BUG: kernel NULL pointer dereference, address: 0000000000000018 RIP: 0010:udp_tunnel6_dst_lookup (net/ipv6/ip6_udp_tunnel.c:160) Call Trace: <TASK> bareudp_fill_metadata_dst (drivers/net/bareudp.c:532) do_execute_actions (net/openvswitch/actions.c:901) ovs_execute_actions (net/openvswitch/actions.c:1589) ovs_packet_cmd_execute (net/openvswitch/datapath.c:700) genl_family_rcv_msg_doit (net/netlink/genetlink.c:1114) genl_rcv_msg (net/netlink/genetlink.c:1209) netlink_rcv_skb (net/netlink/af_netlink.c:2550) </TASK> Add a NULL check returning -ESHUTDOWN, consistent with the xmit paths in the same driver.

References 8

• git.kernel.org https://git.kernel.org/stable/c/31e010a106ff6cd8ccac4bfee547fd3fa1015574
• git.kernel.org https://git.kernel.org/stable/c/35a115a204be08f97450b0389413e218268ef4a2
• git.kernel.org https://git.kernel.org/stable/c/51eef9c072aa3405a6823a96ae666d38a3b48750
• git.kernel.org https://git.kernel.org/stable/c/55193df8d6d33318435f19572bf5ea47a22eee28
• git.kernel.org https://git.kernel.org/stable/c/638905520fc4fae6a80991563f264131545ba3df
• git.kernel.org https://git.kernel.org/stable/c/74a02921c48fcd35a7881956c9e5c52b86595f5d
• git.kernel.org https://git.kernel.org/stable/c/a0f4e4e8e0f5e24ddd83e3d1221732621cf34636
• git.kernel.org https://git.kernel.org/stable/c/aa6c6d9ee064aabfede4402fd1283424e649ca19

Remediation