Kernel security update: CVE-2018-1130 and other; Virtuozzo ReadyKernel patch 52.0 for Virtuozzo 7.0.7 HF3

The cumulative Virtuozzo ReadyKernel patch was updated with security and stability fixes. The patch applies to the Virtuozzo 7.0 kernel 3.10.0-693.21.1.vz7.48.2 (7.0.7 HF3).
Vulnerability id: CVE-2018-1130
Linux kernel before version 4.16-rc7 is vulnerable to a null pointer dereference in dccp_write_xmit() function in net/dccp/output.c in that allows a local user to cause a denial of service by a number of certain crafted system calls.

Vulnerability id: CVE-2018-5803
It was found that _sctp_make_chunk() function did not check if the chunk length for INIT and INIT_ACK packets was within the allowed limits. A local attacker could exploit this to trigger a kernel crash.

Vulnerability id: CVE-2017-17448
It was discovered that nfnl_cthelper_list structure was accessible to any user with CAP_NET_ADMIN capability in a network namespace. An unprivileged local user could exploit that to affect netfilter conntrack helpers on the host.

Vulnerability id: CVE-2017-17449
It was discovered that a nlmon link inside a child network namespace was not restricted to that namespace. An unprivileged local user could exploit that to monitor system-wide netlink activity.

Vulnerability id: CVE-2017-17807
The KEYS subsystem in the Linux kernel omitted an access-control check when writing a key to the current task’s default keyring, allowing a local user to bypass security checks to the keyring. This compromises the validity of the keyring for those who rely on it.

Vulnerability id: CVE-2017-17450
net/netfilter/xt_osf.c in the Linux kernel through 4.14.4 does not require the CAP_NET_ADMIN capability for add_callback and remove_callback operations. This allows local users to bypass intended access restrictions because the xt_osf_fingers data structure is shared across all network namespaces.