Synopsis:          Important: kernel security and bug fix update
Advisory ID:       SLSA-2018:1651-1
Issue Date:        2018-05-22
CVE Numbers:       CVE-2018-3639
--

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.

In this update mitigations for x86 (both 32 and 64 bit) architecture are
provided.

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.
--

SL6
  x86_64
    kernel-2.6.32-696.30.1.el6.x86_64.rpm
    kernel-debug-2.6.32-696.30.1.el6.x86_64.rpm
    kernel-debug-debuginfo-2.6.32-696.30.1.el6.i686.rpm
    kernel-debug-debuginfo-2.6.32-696.30.1.el6.x86_64.rpm
    kernel-debug-devel-2.6.32-696.30.1.el6.i686.rpm
    kernel-debug-devel-2.6.32-696.30.1.el6.x86_64.rpm
    kernel-debuginfo-2.6.32-696.30.1.el6.i686.rpm
    kernel-debuginfo-2.6.32-696.30.1.el6.x86_64.rpm
    kernel-debuginfo-common-i686-2.6.32-696.30.1.el6.i686.rpm
    kernel-debuginfo-common-x86_64-2.6.32-696.30.1.el6.x86_64.rpm
    kernel-devel-2.6.32-696.30.1.el6.x86_64.rpm
    kernel-headers-2.6.32-696.30.1.el6.x86_64.rpm
    perf-2.6.32-696.30.1.el6.x86_64.rpm
    perf-debuginfo-2.6.32-696.30.1.el6.i686.rpm
    perf-debuginfo-2.6.32-696.30.1.el6.x86_64.rpm
    python-perf-debuginfo-2.6.32-696.30.1.el6.i686.rpm
    python-perf-debuginfo-2.6.32-696.30.1.el6.x86_64.rpm
    python-perf-2.6.32-696.30.1.el6.x86_64.rpm
  i386
    kernel-2.6.32-696.30.1.el6.i686.rpm
    kernel-debug-2.6.32-696.30.1.el6.i686.rpm
    kernel-debug-debuginfo-2.6.32-696.30.1.el6.i686.rpm
    kernel-debug-devel-2.6.32-696.30.1.el6.i686.rpm
    kernel-debuginfo-2.6.32-696.30.1.el6.i686.rpm
    kernel-debuginfo-common-i686-2.6.32-696.30.1.el6.i686.rpm
    kernel-devel-2.6.32-696.30.1.el6.i686.rpm
    kernel-headers-2.6.32-696.30.1.el6.i686.rpm
    perf-2.6.32-696.30.1.el6.i686.rpm
    perf-debuginfo-2.6.32-696.30.1.el6.i686.rpm
    python-perf-debuginfo-2.6.32-696.30.1.el6.i686.rpm
    python-perf-2.6.32-696.30.1.el6.i686.rpm
  noarch
    kernel-abi-whitelists-2.6.32-696.30.1.el6.noarch.rpm
    kernel-doc-2.6.32-696.30.1.el6.noarch.rpm
    kernel-firmware-2.6.32-696.30.1.el6.noarch.rpm

- Scientific Linux Development Team