[LU-11042] kernel update [RHEL6.9 2.6.32-696.30.1.el6]

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.10.5
• Severity: 3
• Assignee: Bob Glossman (Inactive)
• Reporter: Bob Glossman (Inactive)

Description

Security Fix(es):

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)

Note: This issue is present in hardware and cannot be fully fixed via software update. The updated kernel packages provide software side of the mitigation for this hardware issue. To be fully functional, up-to-date CPU microcode applied on the system is required.

Bug Fix(es):

Previously, 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. (BZ#1573176)

Issue Links

• is related to: LU-11008 kernel update [RHEL6.9 2.6.32-696.28.1.el6]