Ubuntu Security Notice USN-2908-4
26th February, 2016
linux regression
A security issue affects these releases of Ubuntu and its
derivatives:
- Ubuntu 15.10
Summary
USN-2908-1 introduced a regression in the Linux kernel.
Software description
- linux
– Linux kernel
Details
USN-2908-1 fixed vulnerabilities in the Linux kernel for Ubuntu
15.10. An incorrect locking fix caused a regression that broke
graphics displays for Ubuntu 15.10 guests running within VMWare
virtual machines. This update fixes the problem.
We apologize for the inconvenience.
Original advisory details:
halfdog discovered that OverlayFS, when mounting on top of a FUSE mount,
incorrectly propagated file attributes, including setuid. A local
unprivileged attacker could use this to gain privileges. (CVE-2016-1576)
halfdog discovered that OverlayFS in the Linux kernel incorrectly
propagated security sensitive extended attributes, such as POSIX ACLs. A
local unprivileged attacker could use this to gain privileges.
(CVE-2016-1575)
It was discovered that the Linux kernel did not properly enforce rlimits
for file descriptors sent over UNIX domain sockets. A local attacker could
use this to cause a denial of service. (CVE-2013-4312)
It was discovered that the Linux kernel’s Filesystem in Userspace (FUSE)
implementation did not handle initial zero length segments properly. A
local attacker could use this to cause a denial of service (unkillable
task). (CVE-2015-8785)
Andy Lutomirski discovered a race condition in the Linux kernel’s
translation lookaside buffer (TLB) handling of flush events. A local
attacker could use this to cause a denial of service or possibly leak
sensitive information. (CVE-2016-2069)
Update instructions
The problem can be corrected by updating your system to the following
package version:
- Ubuntu 15.10:
-
linux-image-4.2.0-30-powerpc-smp
4.2.0-30.36
-
linux-image-4.2.0-30-powerpc64-smp
4.2.0-30.36
-
linux-image-4.2.0-30-lowlatency
4.2.0-30.36
-
linux-image-4.2.0-30-powerpc-e500mc
4.2.0-30.36
-
linux-image-4.2.0-30-powerpc64-emb
4.2.0-30.36
-
linux-image-4.2.0-30-generic-lpae
4.2.0-30.36
-
linux-image-4.2.0-30-generic
4.2.0-30.36
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.