USN-3752-2: Linux kernel (HWE) vulnerabilities

24 August 2018

linux-hwe vulnerabilities

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

  • Ubuntu 16.04 LTS

Summary

Several security issues were fixed in the Linux kernel.

Software Description

  • linux-hwe - Linux hardware enablement (HWE) kernel

Details

USN-3752-1 fixed vulnerabilities in the Linux kernel for Ubuntu 18.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 18.04 LTS for Ubuntu 16.04 LTS.

It was discovered that, when attempting to handle an out-of-memory situation, a null pointer dereference could be triggered in the Linux kernel in some circumstances. A local attacker could use this to cause a denial of service (system crash). (CVE-2018-1000200)

Wen Xu discovered that the XFS filesystem implementation in the Linux kernel did not properly validate meta-data information. An attacker could use this to construct a malicious xfs image that, when mounted, could cause a denial of service (system crash). (CVE-2018-10323)

Wen Xu discovered that the XFS filesystem implementation in the Linux kernel did not properly validate xattr information. An attacker could use this to construct a malicious xfs image that, when mounted, could cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-10840)

Wen Xu discovered that the ext4 filesystem implementation in the Linux kernel did not properly keep meta-data information consistent in some situations. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash). (CVE-2018-10881)

Wen Xu discovered that the ext4 filesystem implementation in the Linux kernel did not properly handle corrupted meta data in some situations. An attacker could use this to specially craft an ext4 filesystem that caused a denial of service (system crash) when mounted. (CVE-2018-1093)

Jann Horn discovered that the Linux kernel’s implementation of random seed data reported that it was in a ready state before it had gathered sufficient entropy. An attacker could use this to expose sensitive information. (CVE-2018-1108)

It was discovered that the procfs filesystem did not properly handle processes mapping some memory elements onto files. A local attacker could use this to block utilities that examine the procfs filesystem to report operating system state, such as ps(1). (CVE-2018-1120)

Jann Horn discovered that the ext4 filesystem implementation in the Linux kernel did not properly keep xattr information consistent in some situations. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-11412)

Piotr Gabriel Kosinski and Daniel Shapira discovered a stack-based buffer overflow in the CDROM driver implementation of the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-11506)

Shankara Pailoor discovered that a race condition existed in the socket handling code in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2018-12232)

Shankara Pailoor discovered that the JFS filesystem implementation in the Linux kernel contained a buffer overflow when handling extended attributes. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-12233)

Felix Wilhelm discovered that the KVM implementation in the Linux kernel did not properly perform permission checks in some situations when nested virtualization is used. An attacker in a guest VM could possibly use this to escape into an outer VM or the host OS. (CVE-2018-12904)

Wen Xu discovered that the XFS filesystem implementation in the Linux kernel did not properly handle an error condition with a corrupted xfs image. An attacker could use this to construct a malicious xfs image that, when mounted, could cause a denial of service (system crash). (CVE-2018-13094)

It was discovered that the Linux kernel did not properly handle setgid file creation when performed by a non-member of the group. A local attacker could use this to gain elevated privileges. (CVE-2018-13405)

Silvio Cesare discovered that the generic VESA frame buffer driver in the Linux kernel contained an integer overflow. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-13406)

Jakub Jirasek discovered that multiple use-after-free errors existed in the USB/IP 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-2018-5814)

It was discovered that a race condition existed in the ARM Advanced Microcontroller Bus Architecture (AMBA) driver in the Linux kernel that could result in a double free. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-9415)

It was discovered that an information leak existed in the generic SCSI driver in the Linux kernel. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2018-1000204)

Update instructions

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

Ubuntu 16.04 LTS
linux-image-4.15.0-33-generic - 4.15.0-33.36~16.04.1
linux-image-4.15.0-33-generic-lpae - 4.15.0-33.36~16.04.1
linux-image-4.15.0-33-lowlatency - 4.15.0-33.36~16.04.1
linux-image-generic-hwe-16.04 - 4.15.0.33.55
linux-image-generic-lpae-hwe-16.04 - 4.15.0.33.55
linux-image-lowlatency-hwe-16.04 - 4.15.0.33.55

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