USN-3581-1: Linux kernel vulnerabilities

22 February 2018

linux vulnerabilities

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

  • Ubuntu 17.10

Summary

Several security issues were fixed in the Linux kernel.

Software Description

  • linux - Linux kernel

Details

Mohamed Ghannam discovered that the IPv4 raw socket implementation in the Linux kernel contained a race condition leading to uninitialized pointer usage. A local attacker could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2017-17712)

ChunYu Wang discovered that a use-after-free vulnerability existed in the SCTP protocol implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code, (CVE-2017-15115)

Mohamed Ghannam discovered a use-after-free vulnerability in the DCCP protocol implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-8824)

USN-3541-1 mitigated CVE-2017-5715 (Spectre Variant 2) for the amd64 architecture in Ubuntu 17.10. This update provides the compiler-based retpoline kernel mitigation for the amd64 and i386 architectures. Original advisory details:

Jann Horn discovered that microprocessors utilizing speculative execution and branch prediction may allow unauthorized memory reads via sidechannel attacks. This flaw is known as Spectre. A local attacker could use this to expose sensitive information, including kernel memory. (CVE-2017-5715)

Update instructions

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

Ubuntu 17.10
linux-image-4.13.0-36-generic - 4.13.0-36.40
linux-image-4.13.0-36-generic-lpae - 4.13.0-36.40
linux-image-4.13.0-36-lowlatency - 4.13.0-36.40
linux-image-generic - 4.13.0.36.38
linux-image-generic-lpae - 4.13.0.36.38
linux-image-lowlatency - 4.13.0.36.38

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

After a standard system update you need to reboot your computer to make all the necessary changes.

ATTENTION: Due to an unavoidable ABI change the kernel updates have been given a new version number, which requires you to recompile and reinstall all third party kernel modules you might have installed. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual, linux-powerpc), a standard system upgrade will automatically perform this as well.

References