USN-3654-1: Linux kernel vulnerabilities

22 May 2018

linux, linux-aws, linux-kvm, vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 16.04 LTS

Summary

Several security issues were addressed in the Linux kernel.

Software Description

  • linux - Linux kernel
  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-kvm - Linux kernel for cloud environments

Details

Jann Horn and Ken Johnson discovered that microprocessors utilizing speculative execution of a memory read may allow unauthorized memory reads via a sidechannel attack. This flaw is known as Spectre Variant 4. A local attacker could use this to expose sensitive information, including kernel memory. (CVE-2018-3639)

Tuba Yavuz discovered that a double-free error existed in the USBTV007 driver of the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-17975)

It was discovered that a race condition existed in the F2FS implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2017-18193)

It was discovered that a buffer overflow existed in the Hisilicon HNS Ethernet Device driver in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-18222)

It was discovered that the netfilter subsystem in the Linux kernel did not validate that rules containing jumps contained user-defined chains. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-1065)

It was discovered that the netfilter subsystem of the Linux kernel did not properly validate ebtables offsets. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-1068)

It was discovered that a null pointer dereference vulnerability existed in the DCCP protocol implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2018-1130)

It was discovered that the SCTP Protocol implementation in the Linux kernel did not properly validate userspace provided payload lengths in some situations. A local attacker could use this to cause a denial of service (system crash). (CVE-2018-5803)

It was discovered that a double free error existed in the block layer subsystem of the Linux kernel when setting up a request queue. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-7480)

It was discovered that a memory leak existed in the SAS driver subsystem of the Linux kernel. A local attacker could use this to cause a denial of service (memory exhaustion). (CVE-2018-7757)

It was discovered that a race condition existed in the x86 machine check handler in the Linux kernel. A local privileged attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-7995)

Eyal Itkin discovered that the USB displaylink video adapter driver in the Linux kernel did not properly validate mmap offsets sent from userspace. A local attacker could use this to expose sensitive information (kernel memory) or possibly execute arbitrary code. (CVE-2018-8781)

Silvio Cesare discovered a buffer overwrite existed in the NCPFS implementation in the Linux kernel. A remote attacker controlling a malicious NCPFS server could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-8822)

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 16.04 LTS
linux-image-4.4.0-1026-kvm - 4.4.0-1026.31
linux-image-4.4.0-1060-aws - 4.4.0-1060.69
linux-image-4.4.0-127-generic - 4.4.0-127.153
linux-image-4.4.0-127-generic-lpae - 4.4.0-127.153
linux-image-4.4.0-127-lowlatency - 4.4.0-127.153
linux-image-4.4.0-127-powerpc-e500mc - 4.4.0-127.153
linux-image-4.4.0-127-powerpc-smp - 4.4.0-127.153
linux-image-4.4.0-127-powerpc64-emb - 4.4.0-127.153
linux-image-4.4.0-127-powerpc64-smp - 4.4.0-127.153
linux-image-aws - 4.4.0.1060.62
linux-image-generic - 4.4.0.127.133
linux-image-generic-lpae - 4.4.0.127.133
linux-image-kvm - 4.4.0.1026.25
linux-image-lowlatency - 4.4.0.127.133
linux-image-powerpc-e500mc - 4.4.0.127.133
linux-image-powerpc-smp - 4.4.0.127.133
linux-image-powerpc64-emb - 4.4.0.127.133
linux-image-powerpc64-smp - 4.4.0.127.133

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

Please note that fully mitigating CVE-2018-3639 (Spectre Variant 4) may require corresponding processor microcode/firmware updates or, in virtual environments, hypervisor updates. On i386 and amd64 architectures, the SSBD feature is required to enable the kernel mitigations. BIOS vendors will be making updates available for Intel processors that implement SSBD and Ubuntu is working with Intel to provide future microcode updates. Ubuntu users with a processor from a different vendor should contact the vendor to identify necessary firmware updates. Ubuntu provided corresponding QEMU updates for users of self-hosted virtual environments in USN 3651-1. Ubuntu users in cloud environments should contact the cloud provider to confirm that the hypervisor has been updated to expose the new CPU features to virtual machines.

References