Updated Linux kernel patches has been released for Ubuntu to address the new Intel CPU vulnerabilities
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Kernel Live Patch Security Notice 0059-1
November 12, 2019
linux vulnerability
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A security issue affects these releases of Ubuntu:
| Series | Base kernel | Arch | flavors | |------------------+--------------+----------+------------------|
| Ubuntu 18.04 LTS | 4.15.0 | amd64 | aws | | Ubuntu 18.04 LTS | 4.15.0 | amd64 | generic | | Ubuntu 18.04 LTS | 4.15.0 | amd64 | lowlatency | | Ubuntu 18.04 LTS | 4.15.0 | amd64 | oem | | Ubuntu 18.04 LTS | 5.0.0 | amd64 | azure | | Ubuntu 14.04 LTS | 4.4.0 | amd64 | generic | | Ubuntu 14.04 LTS | 4.4.0 | amd64 | lowlatency | | Ubuntu 16.04 LTS | 4.4.0 | amd64 | aws | | Ubuntu 16.04 LTS | 4.4.0 | amd64 | generic | | Ubuntu 16.04 LTS | 4.4.0 | amd64 | lowlatency | | Ubuntu 16.04 LTS | 4.15.0 | amd64 | azure | | Ubuntu 16.04 LTS | 4.15.0 | amd64 | generic | | Ubuntu 16.04 LTS | 4.15.0 | amd64 | lowlatency |
Summary:
On November 12, fixes for several high-severity Intel processor CVEs were released into the Ubuntu kernel, accompanied by a related processor microcodeupdate. Due to the high complexity of the fixes and the required microcode update, we are unable to livepatch this set of CVEs. Please plan to reboot into an updated kernel as soon as possible.
The details of these CVEs follows:
CVE-2018-12207
On an Ubuntu KVM host configured to use huge pages, a malicious KVM guest can cause a host machine check exception (MCE) capable of bringing down the host OS.
CVE-2019-0154
On Intel processors containing an i915 graphics processing unit, it is possible from userspace to cause a GPU hang in certain low-power states by reading a specific memory-mapped IO register.
CVE-2019-0155
On Intel processors containing an i915 graphics processing unit, it is possible to use the GPU's blitter command streamer to write to memory-mapped IO locations, which could be used for privilege escalation or to leak kernel memory.
CVE-2019-11135
On Intel processors with support for Transactional Synchronization Extensions (TSX), it is possible to exploit a transactional asynchronous abort (TAA) to perform a side-channel attack and leak kernel memory.
Further details on the vulnerabilities and our response can be found here: https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/TAA_MCEPSC_i915
Again, due to the high complexity of the fixes and the required microcode update, we are unable to livepatch this set of CVEs. Please plan to reboot into an updated kernel as soon as possible.
Software Description:
- linux: Linux kernel
Update instructions:
The problem can be corrected by installing an updated kernel with these fixes and rebooting.
| Series | Version | Flavors | |------------------+-----------------------+--------------------------|
| Ubuntu 18.04 LTS | 4.15.0-1054.55 | aws | | Ubuntu 16.04 LTS | 4.4.0-1098.102 | aws | | Ubuntu 18.04 LTS | 5.0.0-1025.27~18.04.1 | azure | | Ubuntu 16.04 LTS | 4.15.0-1063.66 | azure | | Ubuntu 18.04 LTS | 4.15.0-69.78 | generic lowlatency | | Ubuntu 16.04 LTS | 4.15.0-69.78~16.04.1 | generic lowlatency | | Ubuntu 14.04 LTS | 4.4.0-168.197~14.04.1 | generic lowlatency | | Ubuntu 18.04 LTS | 4.15.0-1063.72 | oem | | Ubuntu 16.04 LTS | 4.4.0-168.197 | generic lowlatency |
Support Information:
Kernels older than the levels listed above will no longer receive livepatch updates.
References:
CVE-2018-12207, CVE-2019-0154, CVE-2019-0155, CVE-2019-11135
