Security update for the Linux Kernel

SUSE Security Update: Security update for the Linux Kernel
Announcement ID: SUSE-SU-2018:1377-2
Rating: important
References: #1056427 #1068032 #1075087 #1080157 #1087082 #1090953 #1091041 #1092289 #1093215 #1094019
Cross-References: CVE-2018-3639
Affected Products:
  • SUSE Linux Enterprise Server 12-SP2-BCL

An update that solves one vulnerability and has 9 fixes is now available.

Description:



The SUSE Linux Enterprise 12 SP2 LTSS kernel was updated to receive various security and bugfixes.
The following security bug was 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"
The following related and non-security bugs were fixed:
  • cpuid: Fix cpuid.edx.7.0 propagation to guest
  • ext4: Fix hole length detection in ext4_ind_map_blocks() (bsc#1090953).
  • ibmvnic: Clean actual number of RX or TX pools (bsc#1092289).
  • kvm: Introduce nopvspin kernel parameter (bsc#1056427).
  • kvm: Fix nopvspin static branch init usage (bsc#1056427).
  • powerpc/64: Use barrier_nospec in syscall entry (bsc#1068032, bsc#1080157).
  • powerpc/64s: Add barrier_nospec (bsc#1068032, bsc#1080157).
  • powerpc/64s: Add support for ori barrier_nospec patching (bsc#1068032, bsc#1080157).
  • powerpc/64s: Enable barrier_nospec based on firmware settings (bsc#1068032, bsc#1080157).
  • powerpc/64s: Enhance the information in cpu_show_meltdown() (bsc#1068032, bsc#1075087, bsc#1091041).
  • powerpc/64s: Enhance the information in cpu_show_spectre_v1() (bsc#1068032).
  • powerpc/64s: Fix section mismatch warnings from setup_rfi_flush() (bsc#1068032, bsc#1075087, bsc#1091041).
  • powerpc/64s: Move cpu_show_meltdown() (bsc#1068032, bsc#1075087, bsc#1091041).
  • powerpc/64s: Patch barrier_nospec in modules (bsc#1068032, bsc#1080157).
  • powerpc/64s: Wire up cpu_show_spectre_v1() (bsc#1068032, bsc#1075087, bsc#1091041).
  • powerpc/64s: Wire up cpu_show_spectre_v2() (bsc#1068032, bsc#1075087, bsc#1091041).
  • powerpc/powernv: Set or clear security feature flags (bsc#1068032, bsc#1075087, bsc#1091041).
  • powerpc/powernv: Use the security flags in pnv_setup_rfi_flush() (bsc#1068032, bsc#1075087, bsc#1091041).
  • powerpc/pseries: Add new H_GET_CPU_CHARACTERISTICS flags (bsc#1068032, bsc#1075087, bsc#1091041).
  • powerpc/pseries: Fix clearing of security feature flags (bsc#1068032, bsc#1075087, bsc#1091041).
  • powerpc/pseries: Restore default security feature flags on setup (bsc#1068032, bsc#1075087, bsc#1091041).
  • powerpc/pseries: Set or clear security feature flags (bsc#1068032, bsc#1075087, bsc#1091041).
  • powerpc/pseries: Use the security flags in pseries_setup_rfi_flush() (bsc#1068032, bsc#1075087, bsc#1091041).
  • powerpc/rfi-flush: Always enable fallback flush on pseries (bsc#1068032, bsc#1075087, bsc#1091041).
  • powerpc/rfi-flush: Differentiate enabled and patched flush types (bsc#1068032, bsc#1075087, bsc#1091041).
  • powerpc/rfi-flush: Make it possible to call setup_rfi_flush() again (bsc#1068032, bsc#1075087, bsc#1091041).
  • powerpc: Add security feature flags for Spectre/Meltdown (bsc#1068032, bsc#1075087, bsc#1091041).
  • powerpc: Move default security feature flags (bsc#1068032, bsc#1075087, bsc#1091041).
  • powerpc: Use barrier_nospec in copy_from_user() (bsc#1068032, bsc#1080157).

Special Instructions and Notes:

Please reboot the system after installing this update.

Patch Instructions:

To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
Alternatively you can run the command listed for your product:

  • SUSE Linux Enterprise Server 12-SP2-BCL:
    zypper in -t patch SUSE-SLE-SERVER-12-SP2-BCL-2018-956=1

Package List:

  • SUSE Linux Enterprise Server 12-SP2-BCL (noarch):
    • kernel-devel-4.4.121-92.80.1
    • kernel-macros-4.4.121-92.80.1
    • kernel-source-4.4.121-92.80.1
  • SUSE Linux Enterprise Server 12-SP2-BCL (x86_64):
    • kernel-default-4.4.121-92.80.1
    • kernel-default-base-4.4.121-92.80.1
    • kernel-default-base-debuginfo-4.4.121-92.80.1
    • kernel-default-debuginfo-4.4.121-92.80.1
    • kernel-default-debugsource-4.4.121-92.80.1
    • kernel-default-devel-4.4.121-92.80.1
    • kernel-syms-4.4.121-92.80.1
    • kgraft-patch-4_4_121-92_80-default-1-3.5.2

References: