RHSA-2015:0062 - Security Advisory

Topic

Updated kernel packages that fix multiple security issues, several bugs,
and add one enhancement are now available for Red Hat Enterprise Linux 6.5
Extended Update Support.

Red Hat Product Security has rated this update as having Important security
impact. Common Vulnerability Scoring System (CVSS) base scores, which give
detailed severity ratings, are available for each vulnerability from the
CVE links in the References section.

Description

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

• A flaw was found in the way the Linux kernel's SCTP implementation

handled malformed or duplicate Address Configuration Change Chunks
(ASCONF). A remote attacker could use either of these flaws to crash the
system. (CVE-2014-3673, CVE-2014-3687, Important)

• A flaw was found in the way the Linux kernel's SCTP implementation

handled the association's output queue. A remote attacker could send
specially crafted packets that would cause the system to use an excessive
amount of memory, leading to a denial of service. (CVE-2014-3688,
Important)

• A flaw was found in the way the Linux kernel's VFS subsystem handled

reference counting when performing unmount operations on symbolic links.
A local, unprivileged user could use this flaw to exhaust all available
memory on the system or, potentially, trigger a use-after-free error,
resulting in a system crash or privilege escalation. (CVE-2014-5045,
Moderate)

• An integer overflow flaw was found in the way the lzo1x_decompress_safe()

function of the Linux kernel's LZO implementation processed Literal Runs.
A local attacker could, in extremely rare cases, use this flaw to crash the
system or, potentially, escalate their privileges on the system.
(CVE-2014-4608, Low)

Red Hat would like to thank Vasily Averin of Parallels for reporting
CVE-2014-5045, and Don A. Bailey from Lab Mouse Security for reporting
CVE-2014-4608. The CVE-2014-3673 issue was discovered by Liu Wei of
Red Hat.

This update also fixes several bugs and adds one enhancement.
Documentation for these changes is available from the Technical Notes
document linked to in the References section.

All kernel users are advised to upgrade to these updated packages, which
contain backported patches to correct these issues and add this
enhancement. The system must be rebooted for this update to take effect.

Solution

Before applying this update, make sure all previously released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to use the
Red Hat Network to apply this update are available at
https://access.redhat.com/articles/11258

To install kernel packages manually, use "rpm -ivh [package]". Do not use
"rpm -Uvh" as that will remove the running kernel binaries from your
system. You may use "rpm -e" to remove old kernels after determining that
the new kernel functions properly on your system.

Affected Products

• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.5 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.5 i386
• Red Hat Enterprise Linux Server - AUS 6.5 x86_64
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 6.5 s390x
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.5 ppc64
• Red Hat Enterprise Linux Server - TUS 6.5 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.5 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.5 i386
• Red Hat Enterprise Linux EUS Compute Node 6.5 x86_64

Fixes

• BZ - 1113899 - CVE-2014-4608 kernel: lzo1x_decompress_safe() integer overflow
• BZ - 1122472 - CVE-2014-5045 kernel: vfs: refcount issues during unmount on symlink
• BZ - 1147850 - CVE-2014-3673 kernel: sctp: skb_over_panic when receiving malformed ASCONF chunks
• BZ - 1155731 - CVE-2014-3687 kernel: net: sctp: fix panic on duplicate ASCONF chunks
• BZ - 1155745 - CVE-2014-3688 kernel: net: sctp: remote memory pressure from excessive queueing

CVEs

• CVE-2014-5045
• CVE-2014-4608
• CVE-2014-3687
• CVE-2014-3673
• CVE-2014-3688

References

• https://access.redhat.com/security/updates/classification/#important
• https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/6.5_Technical_Notes/kernel.html