RHSA-2018:2482 - Security Advisory

Topic

An update for docker is now available for Red Hat Enterprise Linux 7 Extras.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

Docker is an open-source engine that automates the deployment of any application as a lightweight, portable, self-sufficient container that runs virtually anywhere.

Security Fix(es):

• docker: container breakout without selinux in enforcing mode (CVE-2018-10892)

For more details about the security issue(s), including the impact, a CVSS score, and other related information, refer to the CVE page(s) listed in the References section.

This issue was discovered by Antonio Murdaca (Red Hat).

Bug Fix(es):

• Previously, the `dontaudit` and `allow` SELinux rules were missing, so the kernel raised a SELinux AVC message. Consequently, some commands did not work as expected. This update adds the missing rules, and the commands now run successfully. (BZ#1550967)
• Previously, during a restart the container daemon did not restore the state of a container correctly if an exec'ed process was associated with the container. Consequently, the container daemon aborted with 'panic: close of nil channel' when the daemon was handling the termination of the exec'ed process. This bug has been fixed, and the container daemon no longer panics in the aforementioned scenario. (BZ#1554121)
• Previously, bind mounts were resolved before using them inside a container. Consequently, symlinks could not be mounted inside of the container. With this update, the source of a bind mount is not resolved. As a result, it is possible to bind mount symlinks again into a container. (BZ#1603201)

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 7 x86_64
• Red Hat Enterprise Linux for IBM z Systems 7 s390x
• Red Hat Enterprise Linux for Power, little endian 7 ppc64le
• Red Hat Enterprise Linux for Power 9 7 ppc64le
• Red Hat Enterprise Linux for IBM System z (Structure A) 7 s390x

Fixes

• BZ - 1550967 - Running systemd in container causes AVC denials about mounton /proc and write core_pattern
• BZ - 1598581 - CVE-2018-10892 docker: container breakout without selinux in enforcing mode
• BZ - 1603201 - [Regression] docker can't bindmount symbolic links to namespaces (/proc/PID/ns/*)

CVEs

• CVE-2018-10892

References

• https://access.redhat.com/security/updates/classification/#moderate