ASA-2018-00091 – Linux kernel: Use-after-free in svc_process_common()

A flaw was found in the Linux kernel in the NFS4 subsystem. NFS41+ shares mounted in different network namespaces at the same time can make bc_svc_process() use wrong back-channel id and cause a use-after-free. Thus a malicious container user can cause a host kernel memory corruption and a system panic. Due to the nature of the flaw, privilege escalation cannot be fully ruled out.