SUSE-SU-2018:1375-1

Описание

The SUSE Linux Enterprise 12 SP1 LTSS kernel was updated to receive various security and bugfixes.

The following security bugs were fixed:

• CVE-2018-3639: Information leaks using 'Memory Disambiguation' feature in modern CPUs were mitigated, aka 'Spectre Variant 4' (bnc#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'

• CVE-2018-1000199: An address corruption flaw was discovered while modifying a h/w breakpoint via 'modify_user_hw_breakpoint' routine, an unprivileged user/process could use this flaw to crash the system kernel resulting in DoS OR to potentially escalate privileges on a the system. (bsc#1089895)

• CVE-2018-10675: The do_get_mempolicy function in mm/mempolicy.c allowed local users to cause a denial of service (use-after-free) or possibly have unspecified other impact via crafted system calls (bnc#1091755).

The following non-security bugs were fixed:

• x86/bugs: Make sure that _TIF_SSBD does not end up in _TIF_ALLWORK_MASK (bsc#1093215).
• x86/bugs: correctly force-disable IBRS on !SKL systems (bsc#1092497).
• x86/cpu/intel: Introduce macros for Intel family numbers (bsc#985025).
• x86/speculation: Remove Skylake C2 from Speculation Control microcode blacklist (bsc#1087845).