Synopsis

Moderate: kernel-rt security, bug fix, and enhancement update

Type/Severity

Security Advisory: Moderate

Topic

Updated kernel-rt packages that fix multiple security issues, several bugs,
and add various enhancements are now available for Red Hat Enterprise
Linux 7.

Red Hat Product Security has rated this update as having Moderate 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-rt packages contain the Linux kernel, the core of any Linux
operating system.

• An integer overflow flaw was found in the way the Linux kernel's
  netfilter connection tracking implementation loaded extensions. An attacker
  on a local network could potentially send a sequence of specially crafted
  packets that would initiate the loading of a large number of extensions,
  causing the targeted system in that network to crash. (CVE-2014-9715,
  Moderate)
  
• A stack-based buffer overflow flaw was found in the Linux kernel's early
  load microcode functionality. On a system with UEFI Secure Boot enabled, a
  local, privileged user could use this flaw to increase their privileges to
  the kernel (ring0) level, bypassing intended restrictions in place.
  (CVE-2015-2666, Moderate)
  
• It was found that the Linux kernel's ping socket implementation did not
  properly handle socket unhashing during spurious disconnects, which could
  lead to a use-after-free flaw. On x86-64 architecture systems, a local user
  able to create ping sockets could use this flaw to crash the system.
  On non-x86-64 architecture systems, a local user able to create ping
  sockets could use this flaw to escalate their privileges on the system.
  (CVE-2015-3636, Moderate)
  
• It was found that the Linux kernel's TCP/IP protocol suite implementation
  for IPv6 allowed the Hop Limit value to be set to a smaller value than the
  default one. An attacker on a local network could use this flaw to prevent
  systems on that network from sending or receiving network packets.
  (CVE-2015-2922, Low)
  

Red Hat would like to thank Nathan Hoad for reporting the CVE-2014-9715
issue.

The kernel-rt packages have been upgraded to version 3.10.0-229.11.1, which
provides a number of bug fixes and enhancements over the previous version,
including:

• drbg: Add stdrng alias and increase priority
  
• seqiv / eseqiv / chainiv: Move IV seeding into init function
  
• ipv4: kABI fix for 0bbf87d backport
  
• ipv4: Convert ipv4.ip_local_port_range to be per netns
  
• libceph: tcp_nodelay support
  
• ipr: Increase default adapter init stage change timeout
  
• fix use-after-free bug in usb_hcd_unlink_urb()
  
• libceph: fix double __remove_osd() problem
  
• ext4: fix data corruption caused by unwritten and delayed extents
  
• sunrpc: Add missing support for RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT
  
• nfs: Fixing lease renewal (Benjamin Coddington)
  
• control hard lockup detection default
  
• Fix print-once on enable
  
• watchdog: update watchdog_thresh properly and watchdog attributes
  atomically
  
• module: Call module notifier on failure after complete_formation()
  

(BZ#1234470)

This update also fixes the following bugs:

• The megasas driver used the smp_processor_id() function within a
  preemptible context, which caused warning messages to be returned to the
  console. The function has been changed to raw_smp_processor_id() so that a
  lock is held while getting the processor ID. As a result, correct
  operations are now allowed without any console warnings being produced.
  (BZ#1235304)
  
• In the NFSv4 file system, non-standard usage of the
  write_seqcount_{begin,end}() functions were used, which caused the realtime
  code to try to sleep while locks were held. As a consequence, the
  "scheduling while atomic" error messages were returned. The underlying
  source code has been modified to use the __write_seqcount_{begin,end}()
  functions that do not hold any locks, allowing correct execution of
  realtime. (BZ#1235301)
  

All kernel-rt users are advised to upgrade to these updated packages, which
correct these issues and add these enhancements. 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.

For details on how to apply this update, refer to:

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

Affected Products

• Red Hat Enterprise Linux for Real Time 7 x86_64

Fixes

• BZ - 1203712 - CVE-2015-2922 kernel: denial of service (DoS) attack against IPv6 network stacks due to improper handling of Router Advertisements.
• BZ - 1204722 - CVE-2015-2666 kernel: execution in the early microcode loader
• BZ - 1208684 - CVE-2014-9715 kernel: netfilter connection tracking extensions denial of service
• BZ - 1218074 - CVE-2015-3636 kernel: ping sockets: use-after-free leading to local privilege escalation
• BZ - 1234470 - kernel-rt: update to the RHEL7.1.z batch 4 source tree

CVEs

• CVE-2014-9715
• CVE-2015-2666
• CVE-2015-2922
• CVE-2015-3636

References

• http://www.redhat.com/security/updates/classification/#normal

Red Hat Enterprise Linux for Real Time 7

SRPM
kernel-rt-3.10.0-229.11.1.rt56.141.11.el7_1.src.rpm	SHA-256: 6965bcbbc0827631bd4e20dc4af7cb2716b3a9e166549640f64ed44c747dd4a4
x86_64
kernel-rt-3.10.0-229.11.1.rt56.141.11.el7_1.x86_64.rpm	SHA-256: f9daabe7f9348148809de6590e1a1d0dd0c8f66ee76642ea7d3918c9e95bb907
kernel-rt-debug-3.10.0-229.11.1.rt56.141.11.el7_1.x86_64.rpm	SHA-256: c9cc37d02ed17966e8ac2883b9e060b79384555b4504ec2114629652351b27d8
kernel-rt-debug-debuginfo-3.10.0-229.11.1.rt56.141.11.el7_1.x86_64.rpm	SHA-256: f4657572a5a7829fc7a0b4deb70cadd6917b9b566b9a92c0416968f14f343c1b
kernel-rt-debug-devel-3.10.0-229.11.1.rt56.141.11.el7_1.x86_64.rpm	SHA-256: 02db89cb54da223e3e7da19786ecb277a301183b76964eb069ba1c122d0bdd35
kernel-rt-debuginfo-3.10.0-229.11.1.rt56.141.11.el7_1.x86_64.rpm	SHA-256: 87d55e14e23f37d1a246f288520ff4597446ec353a934b563f5ad0da6a08809c
kernel-rt-debuginfo-common-x86_64-3.10.0-229.11.1.rt56.141.11.el7_1.x86_64.rpm	SHA-256: 774ab72841354eb42e89a1d0616ccd648948463c950a961d5a515e9dde0b1252
kernel-rt-devel-3.10.0-229.11.1.rt56.141.11.el7_1.x86_64.rpm	SHA-256: d4ab8df5a6bee6cc0f97a2c9a69e6411f28f49ed765a638ebddbaf7f2d141383
kernel-rt-doc-3.10.0-229.11.1.rt56.141.11.el7_1.noarch.rpm	SHA-256: c996beaf90df4a5b168023ba5b24c4f8bcb5c2f5b5259f288ef7a7d459415006
kernel-rt-trace-3.10.0-229.11.1.rt56.141.11.el7_1.x86_64.rpm	SHA-256: 1acf1d3225d95b1c9901196f69ab127e47d24bb497bebcd22a20295ed98a6f23
kernel-rt-trace-debuginfo-3.10.0-229.11.1.rt56.141.11.el7_1.x86_64.rpm	SHA-256: 1318ab2e12899f7b3f29721a8f05d09fb2b518b69276490cdadc506a549ad906
kernel-rt-trace-devel-3.10.0-229.11.1.rt56.141.11.el7_1.x86_64.rpm	SHA-256: 55f046cbede8e0bac5bd6c5948458ef607a3dd2d5aa960a487f7499118ef0561