7.2 - DSA-3804

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

CVE-2016-9588

Jim Mattson discovered that the KVM implementation for Intel x86 processors does not properly handle #BP and #OF exceptions in an L2 (nested) virtual machine. A local attacker in an L2 guest VM can take advantage of this flaw to cause a denial of service for the L1 guest VM.

CVE-2017-2636

Alexander Popov discovered a race condition flaw in the n_hdlc line discipline that can lead to a double free. A local unprivileged user can take advantage of this flaw for privilege escalation. On systems that do not already have the n_hdlc module loaded, this can be mitigated by disabling it: echo >> /etc/modprobe.d/disable-n_hdlc.conf install n_hdlc false

CVE-2017-5669

Gareth Evans reported that privileged users can map memory at address 0 through the shmat() system call. This could make it easier to exploit other kernel security vulnerabilities via a set-UID program.

CVE-2017-5986

Alexander Popov reported a race condition in the SCTP implementation that can be used by local users to cause a denial-of-service (crash). The initial fix for this was incorrect and introduced further security issues (CVE-2017-6353). This update includes a later fix that avoids those. On systems that do not already have the sctp module loaded, this can be mitigated by disabling it: echo >> /etc/modprobe.d/disable-sctp.conf install sctp false

CVE-2017-6214

Dmitry Vyukov reported a bug in the TCP implementation's handling of urgent data in the splice() system call. This can be used by a remote attacker for denial-of-service (hang) against applications that read from TCP sockets with splice().

CVE-2017-6345

Andrey Konovalov reported that the LLC type 2 implementation incorrectly assigns socket buffer ownership. This can be used by a local user to cause a denial-of-service (crash). On systems that do not already have the llc2 module loaded, this can be mitigated by disabling it: echo >> /etc/modprobe.d/disable-llc2.conf install llc2 false

CVE-2017-6346

Dmitry Vyukov reported a race condition in the raw packet (af_packet) fanout feature. Local users with the CAP_NET_RAW capability (in any user namespace) can use this for denial-of-service and possibly for privilege escalation.

CVE-2017-6348

Dmitry Vyukov reported that the general queue implementation in the IrDA subsystem does not properly manage multiple locks, possibly allowing local users to cause a denial-of-service (deadlock) via crafted operations on IrDA devices.

For the stable distribution (jessie), these problems have been fixed in version 3.16.39-1+deb8u2.

We recommend that you upgrade your linux packages.