Security update for the Linux Kernel (important)

The openSUSE Leap 15.0 kernel was updated to receive various security and
bugfixes.

The following security bugs were fixed:

• CVE-2018-3639: Systems with microprocessors utilizing speculative
  execution and speculative execution of memory reads before the addresses
  of all prior memory writes are known may allow unauthorized disclosure
  of information to an attacker with local user access via a side-channel
  analysis, aka Speculative Store Bypass (SSB), Variant 4 (bsc#1087082).

  A new boot commandline option was introduced,
  "spec_store_bypass_disable", which can have following values:

  • auto: Kernel detects whether your CPU model contains an implementation
    of Speculative Store Bypass and picks the most appropriate mitigation.
  • on: disable Speculative Store Bypass
  • off: enable Speculative Store Bypass
  • prctl: Control Speculative Store Bypass per thread via prctl.
    Speculative Store Bypass is enabled for a process by default. The
    state of the control is inherited on fork.
  • seccomp: Same as "prctl" above, but all seccomp threads will disable
    SSB unless they explicitly opt out.

  The default is "seccomp", meaning programs need explicit opt-in into the
  mitigation.

  Status can be queried via the
  /sys/devices/system/cpu/vulnerabilities/spec_store_bypass file, containing:

  • "Vulnerable"
  • "Mitigation: Speculative Store Bypass disabled"
  • "Mitigation: Speculative Store Bypass disabled via prctl"
  • "Mitigation: Speculative Store Bypass disabled via prctl and seccomp"

The following non-security bugs were fixed:

• allow_unsupported: add module tainting on feature use (FATE#323394).
• powerpc/64/kexec: fix race in kexec when XIVE is shutdown (bsc#1088273).
• reiserfs: mark read-write mode unsupported (FATE#323394).
• reiserfs: package in separate KMP (FATE#323394).