5.9 - DSA-3396

Several vulnerabilities have been discovered in the Linux kernel that may lead to a denial of service.

CVE-2015-5307

Ben Serebrin from Google discovered a guest to host denial of service flaw affecting the KVM hypervisor. A malicious guest can trigger an infinite stream of "alignment check" (#AC) exceptions causing the processor microcode to enter an infinite loop where the core never receives another interrupt. This leads to a panic of the host kernel.

CVE-2015-7833

Sergej Schumilo, Hendrik Schwartke and Ralf Spenneberg discovered a flaw in the processing of certain USB device descriptors in the usbvision driver. An attacker with physical access to the system can use this flaw to crash the system.

CVE-2015-7872

Dmitry Vyukov discovered a vulnerability in the keyrings garbage collector allowing a local user to trigger a kernel panic.

CVE-2015-7990

It was discovered that the fix for CVE-2015-6937 was incomplete. A race condition when sending a message on unbound socket can still cause a NULL pointer dereference. A remote attacker might be able to cause a denial of service (crash) by sending a crafted packet.

For the oldstable distribution (wheezy), these problems have been fixed in version 3.2.68-1+deb7u6.

For the stable distribution (jessie), these problems have been fixed in version 3.16.7-ckt11-1+deb8u6.

We recommend that you upgrade your linux packages.