Debian Security Advisory DSA 3804-1 (linux - security update)

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-2017-2636Alexander 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 falseCVE-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-2017-5986Alexander 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 falseCVE-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-2017-6345Andrey 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 falseCVE-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.

linux on Debian Linux

This check tests the installed software version using the apt package manager.

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.