CVE-2017-6074

A use-after-free flaw was found in the way the Linux kernel's Datagram Congestion Control Protocol (DCCP) implementation freed SKB (socket buffer) resources for a DCCP_PKT_REQUEST packet when the IPV6_RECVPKTINFO option is set on the socket. A local, unprivileged user could use this flaw to alter the kernel memory, allowing them to escalate their privileges on the system.

This issue affects Red Hat Enterprise Linux 5, 6, 7, and Red Hat Enterprise MRG 2 kernels.

As this issue is rated as Important, it has been scheduled to be fixed in a future version of Red Hat Enterprise Linux 5, 6, 7, and Red Hat Enterprise MRG 2 kernels.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Recent versions of the SELinux policy can mitigate this flaw. The steps below will work with SELinux enabled or disabled.

As the DCCP module will be auto-loaded when required, its use can be disabled by preventing the module from loading with the following instructions:

echo "install dccp /bin/true" >> /etc/modprobe.d/disable-dccp.conf

The system will need to be restarted if the DCCP modules are loaded. In most circumstances, the DCCP kernel modules will be unable to be unloaded while any network interfaces are active and the protocol is in use.

If you need further assistance, see KCS article https://access.redhat.com/solutions/41278 or contact Red Hat Global Support Services.