Package        : linux-4.9
Version        : 4.9.189-3+deb9u1~deb8u1
CVE ID         : CVE-2019-14821 CVE-2019-14835 CVE-2019-15117 CVE-2019-15118 
                 CVE-2019-15902

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

CVE-2019-14821

    Matt Delco reported a race condition in KVM's coalesced MMIO
    facility, which could lead to out-of-bounds access in the kernel.
    A local attacker permitted to access /dev/kvm could use this to
    cause a denial of service (memory corruption or crash) or possibly
    for privilege escalation.

CVE-2019-14835

    Peter Pi of Tencent Blade Team discovered a missing bounds check
    in vhost_net, the network back-end driver for KVM hosts, leading
    to a buffer overflow when the host begins live migration of a VM.
    An attacker in control of a VM could use this to cause a denial of
    service (memory corruption or crash) or possibly for privilege
    escalation on the host.

CVE-2019-15117

    Hui Peng and Mathias Payer reported a missing bounds check in the
    usb-audio driver's descriptor parsing code, leading to a buffer
    over-read.  An attacker able to add USB devices could possibly use
    this to cause a denial of service (crash).

CVE-2019-15118

    Hui Peng and Mathias Payer reported unbounded recursion in the
    usb-audio driver's descriptor parsing code, leading to a stack
    overflow.  An attacker able to add USB devices could use this to
    cause a denial of service (memory corruption or crash) or possibly
    for privilege escalation.  On the amd64 architecture this is
    mitigated by a guard page on the kernel stack, so that it is only
    possible to cause a crash.

CVE-2019-15902

    Brad Spengler reported that a backporting error reintroduced a
    spectre-v1 vulnerability in the ptrace subsystem in the
    ptrace_get_debugreg() function.

For Debian 8 "Jessie", these problems have been fixed in version
4.9.189-3+deb9u1~deb8u1.

We recommend that you upgrade your linux-4.9 packages.

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

-- 
Ben Hutchings - Debian developer, member of kernel, installer and LTS teams