Important kernel security update: CVE-2018-3639; new kernel 2.6.32-042stab130.1 for Virtuozzo Containers for Linux 4.7, Server Bare Metal 5.0¶
Issue date: 2018-05-23
Applies to: Virtuozzo Containers for Linux 4.7, Server Bare Metal 5.0
Virtuozzo Advisory ID: VZA-2018-032
This update provides a new kernel 2.6.32-042stab130.1 for Virtuozzo Containers for Linux 4.7 and Server Bare Metal 5.0 that is a rebase to the Red Hat Enterprise Linux 6.9 kernel 2.6.32-696.30.1.el6. The new kernel introduces security and stability fixes.
2. Security Fixes¶
[Important] An industry-wide issue was found in the way many modern microprocessor designs have implemented speculative execution of Load & Store instructions (a commonly used performance optimization). It relies on the presence of a precisely-defined instruction sequence in the privileged code as well as the fact that memory read from address to which a recent memory write has occurred may see an older value and subsequently cause an update into the microprocessor’s data cache even for speculatively executed instructions that never actually commit (retire). As a result, an unprivileged attacker could use this flaw to read privileged memory by conducting targeted cache side-channel attacks. (CVE-2018-3639)
3. Bug Fixes¶
Memory corruption after execution of vzreboot on the 042stab129.1 kernel. The issue was inherited from Red Hat kernel 2.6.32-696.28.1.el6: “An erroneous code in the x86 kexec system call path caused a memory corruption. As a consequence, the system became unresponsive with the following kernel stack trace: ‘WARNING: CPU: 13 PID: 36409 at lib/list_debug.c:59 __list_del_entry+0xa1/0xd0 list_del corruption. prev->next should be ffffdd03fddeeca0, but was (null)’. This update ensures that the code does not corrupt memory. As a result, the operating system no longer hangs.” (RHBZ#1573176, PSBM-84796)
4. Installing the Update¶
Install the update with the ‘vzup2date’ utility included in the distribution.
The JSON file with the list of new and updated packages is available at http://docs.virtuozzo.com/vza/VZA-2018-032.json.