[SECURITY] [DSA 3364-1] linux security update

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Debian Security Advisory DSA-3364-1                   security@debian.org
https://www.debian.org/security/                            Ben Hutchings
September 21, 2015                    https://www.debian.org/security/faq
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Package        : linux
CVE ID         : CVE-2015-0272 CVE-2015-2925 CVE-2015-5156 CVE-2015-6252
                 CVE-2015-6937
Debian Bug     : 796036

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

CVE-2015-0272

    It was discovered that NetworkManager would set IPv6 MTUs based on
    the values received in IPv6 RAs (Router Advertisements), without
    sufficiently validating these values. A remote attacker could
    exploit this attack to disable IPv6 connectivity. This has been
    mitigated by adding validation in the kernel.

CVE-2015-2925

    Jann Horn discovered that when a subdirectory of a filesystem is
    bind-mounted into a container that has its own user and mount
    namespaces, a process with CAP_SYS_ADMIN capability in the user
    namespace can access files outside of the subdirectory.  The
    default Debian configuration mitigated this as it does not allow
    unprivileged users to create new user namespaces.

CVE-2015-5156

    Jason Wang discovered that when a virtio_net device is connected
    to a bridge in the same VM, a series of TCP packets forwarded
    through the bridge may cause a heap buffer overflow.  A remote
    attacker could use this to cause a denial of service (crash) or
    possibly for privilege escalation.

CVE-2015-6252

    Michael S. Tsirkin of Red Hat Engineering found that the vhost
    driver leaked file descriptors passed to it with the
    VHOST_SET_LOG_FD ioctl command. A privileged local user with access
    to the /dev/vhost-net file, either directly or via libvirt, could
    use this to cause a denial of service (hang or crash).

CVE-2015-6937

    It was found that the Reliable Datagram Sockets (RDS) protocol
    implementation did not verify that an underlying transport exists
    when creating a connection.  Depending on how a local RDS
    application initialised its sockets, a remote attacker might be
    able to cause a denial of service (crash) by sending a crafted
    packet.

#796036

    Xavier Chantry discovered that the patch provided by the aufs
    project to correct behaviour of memory-mapped files from an aufs
    mount introduced a race condition in the msync() system call.
    Ben Hutchings found that it also introduced a similar bug in the
    madvise_remove() function.  A local attacker could use this to
    cause a denial of service or possibly for privilege escalation.

For the oldstable distribution (wheezy), these problems have been fixed
in version 3.2.68-1+deb7u4. CVE-2015-2925 and #796036 do not affect the
wheezy distribution.

For the stable distribution (jessie), these problems have been fixed in
version 3.16.7-ckt11-1+deb8u4.

We recommend that you upgrade your linux packages.

Further information about Debian Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://www.debian.org/security/