Ubuntu Security Notice USN-2907-2
22nd February, 2016
linux-lts-trusty vulnerabilities
A security issue affects these releases of Ubuntu and its
derivatives:
Summary
Several security issues were fixed in the kernel.
Software description
- linux-lts-trusty
– Linux hardware enablement kernel from Trusty
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 keyring subsystem contained a race
between read and revoke operations. A local attacker could use this to
cause a denial of service (system crash). (CVE-2015-7550)
郭永刚 discovered that the Linux kernel networking implementation did
not validate protocol identifiers for certain protocol families, A local
attacker could use this to cause a denial of service (system crash) or
possibly gain administrative privileges. (CVE-2015-8543)
Dmitry Vyukov discovered that the pptp implementation in the Linux kernel
did not verify an address length when setting up a socket. A local attacker
could use this to craft an application that exposed sensitive information
from kernel memory. (CVE-2015-8569)
David Miller discovered that the Bluetooth implementation in the Linux
kernel did not properly validate the socket address length for Synchronous
Connection-Oriented (SCO) sockets. A local attacker could use this to
expose sensitive information. (CVE-2015-8575)
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)
Update instructions
The problem can be corrected by updating your system to the following
package version:
- Ubuntu 12.04 LTS:
-
linux-image-3.13.0-79-generic-lpae
3.13.0-79.123~precise1
-
linux-image-3.13.0-79-generic
3.13.0-79.123~precise1
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-2015-7550,
CVE-2015-8543,
CVE-2015-8569,
CVE-2015-8575,
CVE-2015-8785,
CVE-2016-1575,
CVE-2016-1576