Important kernel security update: CVE-2018-5391 and other issues; new kernel 2.6.32-042stab134.3; Virtuozzo 6.0 Update 12 Hotfix 33 (6.0.12-3724)

Issue date: 2018-10-15

Applies to: Virtuozzo 6.0

Virtuozzo Advisory ID: VZA-2018-075

1. Overview

This update provides a new kernel 2.6.32-042stab134.3 for Virtuozzo 6.0. The new kernel introduces security and stability fixes.

2. Security Fixes

  • [Important] A flaw named FragmentSmack was found in the way the Linux kernel handled reassembly of fragmented IPv4 and IPv6 packets. A remote attacker could use this flaw to trigger time and calculation expensive fragment reassembly algorithm by sending specially crafted packets which could lead to a CPU saturation and hence a denial of service on the system. (CVE-2018-5391)

  • [Important] An integer overflow flaw was found in the Linux kernel’s create_elf_tables() function. An unprivileged local user with access to SUID (or otherwise privileged) binary could use this flaw to escalate their privileges on the system (Mutagen Astronomy). (CVE-2018-14634)

  • [Low] The Linux Kernel imposes a size restriction on the arguments and environmental strings passed through RLIMIT_STACK/RLIMIT_INFINITY, but does not take the argument and environment pointers into account, which allows attackers to bypass this limitation. (CVE-2017-1000365)

3. Bug Fixes

  • Under certain circumstances, ploop could crash after failed execution of kernel thread. (PSBM-88559)

  • Under certain circumstances, Acronis Backup could trigger host crash in blk_cbt_update_size(). (PSBM-88570)

  • Under certain circumstances, host could crash inside Acronis snumbd driver. (PSBM-88575)

  • Under certain circumstances, Acronis Backup could trigger host hard lockup in __cbt_flush_cpu_cache. (PSBM-89323)

  • Fixed locking in blk_release_queue() that led to hard lockup in blk_throtl_drain() (was broken in 2.6.32-754.6.3.el6 RHEL6 kernel). (PSBM-89391, RHBZ#1638926)

4. Installing the Update

Install the update by running ‘yum update’.