6.9 - DSA-3434

Several vulnerabilities have been discovered in the Linux kernel that may lead to a privilege escalation, denial of service or information leak.

CVE-2015-7513

It was discovered that a local user permitted to use the x86 KVM subsystem could configure the PIT emulation to cause a denial of service (crash).

CVE-2015-7550

Dmitry Vyukov discovered a race condition in the keyring subsystem that allows a local user to cause a denial of service (crash).

CVE-2015-8543

It was discovered that a local user permitted to create raw sockets could cause a denial-of-service by specifying an invalid protocol number for the socket. The attacker must have the CAP_NET_RAW capability.

CVE-2015-8550

Felix Wilhelm of ERNW discovered that the Xen PV backend drivers may read critical data from shared memory multiple times. This flaw can be used by a guest kernel to cause a denial of service (crash) on the host, or possibly for privilege escalation.

CVE-2015-8551 / CVE-2015-8552

Konrad Rzeszutek Wilk of Oracle discovered that the Xen PCI backend driver does not adequately validate the device state when a guest configures MSIs. This flaw can be used by a guest kernel to cause a denial of service (crash or disk space exhaustion) on the host.

CVE-2015-8569

Dmitry Vyukov discovered a flaw in the PPTP sockets implementation that leads to an information leak to local users.

CVE-2015-8575

David Miller discovered a flaw in the Bluetooth SCO sockets implementation that leads to an information leak to local users.

CVE-2015-8709

Jann Horn discovered a flaw in the permission checks for use of the ptrace feature. A local user who has the CAP_SYS_PTRACE capability within their own user namespace could use this flaw for privilege escalation if a more privileged process ever enters that user namespace. This affects at least the LXC system.

In addition, this update fixes some regressions in the previous update:

#808293

A regression in the UDP implementation prevented freeradius and some other applications from receiving data.

#808602 / #808953

A regression in the USB XHCI driver prevented use of some devices in USB 3 SuperSpeed ports.

#808973

A fix to the radeon driver interacted with an existing bug to cause a crash at boot when using some AMD/ATI graphics cards. This issue only affects wheezy.

For the oldstable distribution (wheezy), these problems have been fixed in version 3.2.73-2+deb7u2. The oldstable distribution (wheezy) is not affected by CVE-2015-8709.

For the stable distribution (jessie), these problems have been fixed in version 3.16.7-ckt20-1+deb8u2. CVE-2015-8543 was already fixed in version 3.16.7-ckt20-1+deb8u1.

For the unstable distribution (sid), these problems have been fixed in version 4.3.3-3 or earlier.

We recommend that you upgrade your linux packages.