==========================================================================
Kernel Live Patch Security Notice 0055-1
September 06, 2019
linux vulnerability
==========================================================================
A security issue affects these releases of Ubuntu:
| Series | Base kernel | Arch | flavors |
|——————+————–+———-+——————|
| Ubuntu 18.04 LTS | 4.15.0 | amd64 | generic |
| Ubuntu 18.04 LTS | 4.15.0 | amd64 | lowlatency |
| Ubuntu 16.04 LTS | 4.4.0 | amd64 | generic |
| Ubuntu 16.04 LTS | 4.4.0 | amd64 | lowlatency |
| Ubuntu 16.04 LTS | 4.15.0 | amd64 | generic |
| Ubuntu 16.04 LTS | 4.15.0 | 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 error existed in the block layer
subsystem of the Linux kernel when certain failure conditions occurred. A
local attacker could possibly use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2018-20856)
It was discovered that the Bluetooth UART implementation in the Linux
kernel did not properly check for missing tty operations. A local attacker
could use this to cause a denial of service. (CVE-2019-10207)
Jonathan Looney discovered that the TCP retransmission queue implementation
in the Linux kernel could be fragmented when handling certain TCP Selective
Acknowledgment (SACK) sequences. A remote attacker could use this to cause
a denial of service. (CVE-2019-11478)
Jann Horn discovered a use-after-free vulnerability in the Linux kernel
when accessing LDT entries in some situations. A local attacker could use
this to cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2019-13233)
It was discovered that the floppy driver in the Linux kernel did not
properly validate meta data, leading to a buffer overread. A local attacker
could use this to cause a denial of service (system crash).
(CVE-2019-14283)
It was discovered that the floppy driver in the Linux kernel did not
properly validate ioctl() calls, leading to a division-by-zero. A local
attacker could use this to cause a denial of service (system crash).
(CVE-2019-14284)
Update instructions:
The problem can be corrected by updating your livepatches to the following
versions:
| Kernel | Version | flavors |
|————————–+———-+————————–|
| 4.4.0-148.174 | 55.1 | lowlatency, generic |
| 4.4.0-150.176 | 55.1 | generic, lowlatency |
| 4.4.0-151.178 | 55.1 | lowlatency, generic |
| 4.4.0-154.181 | 55.1 | lowlatency, generic |
| 4.4.0-157.185 | 55.1 | lowlatency |
| 4.4.0-159.187 | 55.1 | lowlatency, generic |
| 4.15.0-50.54 | 55.1 | generic, lowlatency |
| 4.15.0-50.54~16.04.1 | 55.1 | generic, lowlatency |
| 4.15.0-51.55 | 55.1 | generic, lowlatency |
| 4.15.0-51.55~16.04.1 | 55.2 | generic, lowlatency |
| 4.15.0-52.56 | 55.1 | lowlatency, generic |
| 4.15.0-52.56~16.04.1 | 55.1 | generic, lowlatency |
| 4.15.0-54.58 | 55.1 | generic, lowlatency |
| 4.15.0-54.58~16.04.1 | 55.1 | generic, lowlatency |
| 4.15.0-55.60 | 55.1 | generic, lowlatency |
| 4.15.0-58.64 | 55.1 | generic, lowlatency |
| 4.15.0-58.64~16.04.1 | 55.1 | lowlatency, generic |
Support Information:
Kernels older than the levels listed below do not receive livepatch
updates. Please upgrade your kernel as soon as possible.
| Series | Version | Flavors |
|——————+——————+————————–|
| Ubuntu 18.04 LTS | 4.15.0-50 | generic lowlatency |
| Ubuntu 16.04 LTS | 4.15.0-50 | generic lowlatency |
| Ubuntu 16.04 LTS | 4.4.0-148 | generic lowlatency |
| Ubuntu 14.04 LTS | 4.4.0-148 | generic lowlatency |
References:
CVE-2018-20856, CVE-2019-10207, CVE-2019-11478, CVE-2019-13233,
CVE-2019-14283, CVE-2019-14284
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