==========================================================================
Kernel Live Patch Security Notice LSN-0026-1
July 24, 2017

linux vulnerability
==========================================================================

A security issue affects these releases of Ubuntu:

| Series | Base kernel | Arch | flavors |
|——————+————–+———-+——————|
| Ubuntu 16.04 LTS | 4.4.0 | amd64 | generic |
| Ubuntu 16.04 LTS | 4.4.0 | amd64 | lowlatency |
| Ubuntu 14.04 LTS | 4.4.0 | amd64 | generic |
| Ubuntu 14.04 LTS | 4.4.0 | amd64 | lowlatency |

Summary:

Several security issues were fixed in the kernel.

Software Description:
– linux: Linux kernel

Details:

It was discovered that a use-after-free flaw existed in the filesystem
encryption subsystem in the Linux kernel. A local attacker could use this
to cause a denial of service (system crash). (CVE-2017-7374)

Jann Horn discovered that the extended Berkeley Packet Filter (eBPF)
implementation in the Linux kernel could overflow reference counters on
systems with more than 32GB of physical ram and with RLIMIT_MEMLOCK set to
infinite. A local unprivileged attacker could use to create a use-after-
free situation, causing a denial of service (system crash) or possibly gain
administrative privileges. (CVE-2016-4558)

It was discovered that the Linux kernel did not properly restrict
RLIMIT_STACK size. A local attacker could use this in conjunction with
another vulnerability to possibly execute arbitrary code.
(CVE-2017-1000365)

石磊 discovered that the RxRPC Kerberos 5 ticket handling code in the
Linux kernel did not properly verify metadata. A remote attacker could use
this to cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2017-7482)

Jann Horn discovered that bpf in Linux kernel does not restrict the output
of the print_bpf_insn function. A local attacker could use this to obtain
sensitive address information. (CVE-2017-9150)

Update instructions:

The problem can be corrected by updating your livepatches to the following
versions:

| Kernel | Version | flavors |
|—————–+———-+————————–|
| 4.4.0-21.37 | 26.1 | generic, lowlatency |
| 4.4.0-22.39 | 26.1 | generic, lowlatency |
| 4.4.0-22.40 | 26.1 | generic, lowlatency |
| 4.4.0-24.43 | 26.1 | generic, lowlatency |
| 4.4.0-28.47 | 26.1 | generic, lowlatency |
| 4.4.0-31.50 | 26.1 | generic, lowlatency |
| 4.4.0-34.53 | 26.1 | generic, lowlatency |
| 4.4.0-36.55 | 26.1 | generic, lowlatency |
| 4.4.0-38.57 | 26.1 | generic, lowlatency |
| 4.4.0-42.62 | 26.1 | generic, lowlatency |
| 4.4.0-43.63 | 26.1 | generic, lowlatency |
| 4.4.0-45.66 | 26.1 | generic, lowlatency |
| 4.4.0-47.68 | 26.1 | generic, lowlatency |
| 4.4.0-51.72 | 26.1 | generic, lowlatency |
| 4.4.0-53.74 | 26.1 | generic, lowlatency |
| 4.4.0-57.78 | 26.1 | generic, lowlatency |
| 4.4.0-59.80 | 26.1 | generic, lowlatency |
| 4.4.0-62.83 | 26.1 | generic, lowlatency |
| 4.4.0-63.84 | 26.1 | generic, lowlatency |
| 4.4.0-64.85 | 26.1 | generic, lowlatency |
| 4.4.0-66.87 | 26.1 | generic, lowlatency |
| 4.4.0-67.88 | 26.1 | generic, lowlatency |
| 4.4.0-70.91 | 26.1 | generic, lowlatency |
| 4.4.0-71.92 | 26.1 | generic, lowlatency |
| 4.4.0-72.93 | 26.1 | generic, lowlatency |
| 4.4.0-75.96 | 26.1 | generic, lowlatency |
| 4.4.0-77.98 | 26.1 | generic, lowlatency |
| 4.4.0-78.99 | 26.1 | generic, lowlatency |
| 4.4.0-79.100 | 26.1 | generic, lowlatency |
| 4.4.0-81.104 | 26.1 | generic, lowlatency |
| 4.4.0-83.106 | 26.1 | generic, lowlatency |
| lts-4.4.0-21.37_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-22.39_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-22.40_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-24.43_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-28.47_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-31.50_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-34.53_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-36.55_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-38.57_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-42.62_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-45.66_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-47.68_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-51.72_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-53.74_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-57.78_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-59.80_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-62.83_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-64.85_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-66.87_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-70.91_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-71.92_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-72.93_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-75.96_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-79.100_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |
| lts-4.4.0-81.104_14.04.1-lts-xenial | 14.04.1 | generic, lowlatency |

Additionally, you should install an updated kernel with these fixes and
reboot at your convienience.

References:
CVE-2016-4558, CVE-2017-1000365, CVE-2017-7374, CVE-2017-7482,
CVE-2017-9150

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