USN-3377-2: Linux kernel (HWE) vulnerabilities

Ubuntu Security Notice USN-3377-2

3rd August, 2017

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-3377-1 fixed vulnerabilities in the Linux kernel for Ubuntu 17.04.
This update provides the corresponding updates for the Linux
Hardware Enablement (HWE) kernel from Ubuntu 17.04 for Ubuntu
16.04 LTS.

Fan Wu and Shixiong Zhao discovered a race condition between inotify events
and vfs rename operations in the Linux kernel. An unprivileged local
attacker could use this to cause a denial of service (system crash) or
execute arbitrary code. (CVE-2017-7533)

It was discovered that the Linux kernel did not properly restrict
RLIMIT_STACK size. A local attacker could use this in conjunction with
another vulnerability to possibly execute arbitrary code.
(CVE-2017-1000365)

李强 discovered that the Virtio GPU driver in the Linux kernel did not
properly free memory in some situations. A local attacker could use this to
cause a denial of service (memory consumption). (CVE-2017-10810)

石磊 discovered that the RxRPC Kerberos 5 ticket handling code in the
Linux kernel did not properly verify metadata. A remote attacker could use
this to cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2017-7482)

Update instructions

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

Ubuntu 16.04 LTS:
linux-image-4.10.0-30-generic-lpae 4.10.0-30.34~16.04.1
linux-image-generic-hwe-16.04 4.10.0.30.33
linux-image-lowlatency-hwe-16.04 4.10.0.30.33
linux-image-4.10.0-30-generic 4.10.0-30.34~16.04.1
linux-image-4.10.0-30-lowlatency 4.10.0-30.34~16.04.1
linux-image-generic-lpae-hwe-16.04 4.10.0.30.33

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

CVE-2017-1000365, CVE-2017-10810, CVE-2017-7482, CVE-2017-7533