RHSA-2017:2863 - Security Advisory

Topic

An update for kernel is now available for Red Hat Enterprise Linux 6.

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

The kernel packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

• Kernel memory corruption due to a buffer overflow was found in brcmf_cfg80211_mgmt_tx() function in Linux kernels from v3.9-rc1 to v4.13-rc1. The vulnerability can be triggered by sending a crafted NL80211_CMD_FRAME packet via netlink. This flaw is unlikely to be triggered remotely as certain userspace code is needed for this. An unprivileged local user could use this flaw to induce kernel memory corruption on the system, leading to a crash. Due to the nature of the flaw, privilege escalation cannot be fully ruled out, although it is unlikely. (CVE-2017-7541, Moderate)

Bug Fix(es):

• Previously, removal of a rport during ISCSI target scanning could cause a kernel panic. This was happening because addition of STARGET_REMOVE to the rport state introduced a race condition to the SCSI code. This update adds the STARGET_CREATED_REMOVE state as a possible state of the rport and appropriate handling of that state, thus fixing the bug. As a result, the kernel panic no longer occurs under the described circumstances. (BZ#1472127)
• Previously, GFS2 contained multiple bugs where the wrong inode was assigned to GFS2 cluster-wide locks (glocks), or the assigned inode was cleared incorrectly. Consequently, kernel panic could occur when using GFS2. With this update, GFS2 has been fixed, and the kernel no longer panics due to those bugs. (BZ#1479397)
• Previously, VMs with memory larger than 64GB running on Hyper-V with Windows Server hosts reported potential memory size of 4TB and more, but could not use more than 64GB. This was happening because the Memory Type Range Register (MTRR) for memory above 64GB was omitted. With this update, the /proc/mtrr file has been fixed to show correct base/size if they are more than 44 bit wide. As a result, the whole size of memory is now available as expected under the described circumstances. (BZ#1482855)

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

The system must be rebooted for this update to take effect.

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

• BZ - 1473198 - CVE-2017-7541 kernel: Possible heap buffer overflow in brcmf_cfg80211_mgmt_tx()

CVEs

• CVE-2017-7541

References

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