Ubuntu Security Notice 3695-1 - Wen Xu discovered that the ext4 file system implementation in the Linux kernel did not properly initialize the crc32c checksum driver. A local attacker could use this to cause a denial of service. It was discovered that the cdrom driver in the Linux kernel contained an incorrect bounds check. A local attacker could use this to expose sensitive information. Various other issues were also addressed.
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Ubuntu Security Notice USN-3695-1
July 02, 2018
linux, linux-aws, linux-azure, linux-gcp, linux-kvm, linux-oem, linux-raspi2 vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 18.04 LTS
Summary:
Several security issues were fixed in the Linux kernel.
Software Description:
- linux: Linux kernel
- linux-aws: Linux kernel for Amazon Web Services (AWS) systems
- linux-azure: Linux kernel for Microsoft Azure Cloud systems
- linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems
- linux-kvm: Linux kernel for cloud environments
- linux-oem: Linux kernel for OEM processors
- linux-raspi2: Linux kernel for Raspberry Pi 2
Details:
Wen Xu discovered that the ext4 file system implementation in the Linux
kernel did not properly initialize the crc32c checksum driver. A local
attacker could use this to cause a denial of service (system crash).
(CVE-2018-1094)
It was discovered that the cdrom driver in the Linux kernel contained an
incorrect bounds check. A local attacker could use this to expose sensitive
information (kernel memory). (CVE-2018-10940)
Wen Xu discovered that the ext4 file system implementation in the Linux
kernel did not properly validate xattr sizes. A local attacker could use
this to cause a denial of service (system crash). (CVE-2018-1095)
Jann Horn discovered that the 32 bit adjtimex() syscall implementation for
64 bit Linux kernels did not properly initialize memory returned to user
space in some situations. A local attacker could use this to expose
sensitive information (kernel memory). (CVE-2018-11508)
It was discovered that an information leak vulnerability existed in the
floppy driver in the Linux kernel. A local attacker could use this to
expose sensitive information (kernel memory). (CVE-2018-7755)
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 18.04 LTS:
linux-image-4.15.0-1010-gcp 4.15.0-1010.10
linux-image-4.15.0-1011-aws 4.15.0-1011.11
linux-image-4.15.0-1012-kvm 4.15.0-1012.12
linux-image-4.15.0-1013-raspi2 4.15.0-1013.14
linux-image-4.15.0-1014-azure 4.15.0-1014.14
linux-image-4.15.0-24-generic 4.15.0-24.26
linux-image-4.15.0-24-generic-lpae 4.15.0-24.26
linux-image-4.15.0-24-lowlatency 4.15.0-24.26
linux-image-4.15.0-24-snapdragon 4.15.0-24.26
linux-image-aws 4.15.0.1011.11
linux-image-azure 4.15.0.1014.14
linux-image-gcp 4.15.0.1010.12
linux-image-generic 4.15.0.24.26
linux-image-generic-lpae 4.15.0.24.26
linux-image-gke 4.15.0.1010.12
linux-image-kvm 4.15.0.1012.12
linux-image-lowlatency 4.15.0.24.26
linux-image-oem 4.15.0.1009.11
linux-image-raspi2 4.15.0.1013.11
linux-image-snapdragon 4.15.0.24.26
After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.
References:
https://usn.ubuntu.com/usn/usn-3695-1
CVE-2018-1094, CVE-2018-10940, CVE-2018-1095, CVE-2018-11508,
CVE-2018-7755
Package Information:
https://launchpad.net/ubuntu/+source/linux/4.15.0-24.26
https://launchpad.net/ubuntu/+source/linux-aws/4.15.0-1011.11
https://launchpad.net/ubuntu/+source/linux-azure/4.15.0-1014.14
https://launchpad.net/ubuntu/+source/linux-gcp/4.15.0-1010.10
https://launchpad.net/ubuntu/+source/linux-kvm/4.15.0-1012.12
https://launchpad.net/ubuntu/+source/linux-oem/4.15.0-1009.12
https://launchpad.net/ubuntu/+source/linux-raspi2/4.15.0-1013.14