CVE-2026-45846
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk2th percentile - higher than 2% of all known CVEs
Summary
In the Linux kernel, a vulnerability was found in the bareudp driver where the bareudp_fill_metadata_dst() function is called without checking if the socket exists. When the network device is down, the socket is NULL, leading to a NULL pointer dereference and system crash.
Risk Assessment
An attacker can intentionally trigger this vulnerability by sending specially crafted packets to a disabled bareudp interface, causing a denial of service (DoS) through system hang or reboot.
Recommendation
Immediately update the Linux kernel to a version containing the fix, which adds a NULL check and returns -ESHUTDOWN error code, consistent with other transmit paths in the same driver.
Original NVD description (English source)
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.