[RHSA-2015:2411-01] Important: kernel-rt security, bug fix, and enhancement update

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Red Hat Security Advisory

 

Synopsis: Important: kernel-rt security, bug fix, and enhancement update

Advisory ID: RHSA-2015:2411-01

Product: Red Hat Enterprise Linux

Advisory URL: https://rhn.redhat.com/errata/RHSA-2015-2411.html

Issue date: 2015-11-19

CVE Names: CVE-2013-7421 CVE-2014-8171 CVE-2014-9419

CVE-2014-9644 CVE-2015-2925 CVE-2015-3339

CVE-2015-4170 CVE-2015-5283 CVE-2015-7613

CVE-2015-7837

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1. Summary:

 

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 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.

 

2. Relevant releases/architectures:

 

Red Hat Enterprise Linux for Real Time (v. 7) - noarch, x86_64

 

3. Description:

 

The kernel-rt packages contain the Linux kernel, the core of any Linux

operating system.

 

* A flaw was found in the way the Linux kernel's file system implementation

handled rename operations in which the source was inside and the

destination was outside of a bind mount. A privileged user inside a

container could use this flaw to escape the bind mount and, potentially,

escalate their privileges on the system. (CVE-2015-2925, Important)

 

* A race condition flaw was found in the way the Linux kernel's IPC

subsystem initialized certain fields in an IPC object structure that were

later used for permission checking before inserting the object into a

globally visible list. A local, unprivileged user could potentially use

this flaw to elevate their privileges on the system. (CVE-2015-7613,

Important)

 

* It was found that the Linux kernel memory resource controller's (memcg)

handling of OOM (out of memory) conditions could lead to deadlocks.

An attacker able to continuously spawn new processes within a single

memory-constrained cgroup during an OOM event could use this flaw to lock

up the system. (CVE-2014-8171, Moderate)

 

* A race condition flaw was found between the chown and execve system

calls. When changing the owner of a setuid user binary to root, the race

condition could momentarily make the binary setuid root. A local,

unprivileged user could potentially use this flaw to escalate their

privileges on the system. (CVE-2015-3339, Moderate)

 

* A flaw was discovered in the way the Linux kernel's TTY subsystem handled

the tty shutdown phase. A local, unprivileged user could use this flaw to

cause a denial of service on the system by holding a reference to the ldisc

lock during tty shutdown, causing a deadlock. (CVE-2015-4170, Moderate)

 

* A NULL pointer dereference flaw was found in the SCTP implementation.

A local user could use this flaw to cause a denial of service on the system

by triggering a kernel panic when creating multiple sockets in parallel

while the system did not have the SCTP module loaded. (CVE-2015-5283,

Moderate)

 

* A flaw was found in the way the Linux kernel's Crypto subsystem handled

automatic loading of kernel modules. A local user could use this flaw to

load any installed kernel module, and thus increase the attack surface of

the running kernel. (CVE-2013-7421, CVE-2014-9644, Low)

 

* An information leak flaw was found in the way the Linux kernel changed

certain segment registers and thread-local storage (TLS) during a context

switch. A local, unprivileged user could use this flaw to leak the user

space TLS base address of an arbitrary process. (CVE-2014-9419, Low)

 

* A flaw was found in the way the Linux kernel handled the securelevel

functionality after performing a kexec operation. A local attacker could

use this flaw to bypass the security mechanism of the

securelevel/secureboot combination. (CVE-2015-7837, Low)

 

Red Hat would like to thank Linn Crosetto of HP for reporting the

CVE-2015-7837 issue. The CVE-2015-5283 issue was discovered by Ji Jianwen

from Red Hat engineering.

 

The kernel-rt packages have been upgraded to version 3.10.0-326.rt56.204,

which provides a number of bug fixes and enhancements. (BZ#1201915,

BZ#1211724)

 

This update also fixes several bugs and adds multiple enhancements.

Refer to the following Red Hat Knowledgebase article for information on the

most significant of these changes:

 

https://access.redhat.com/articles/2055783

 

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.

 

4. 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

 

5. Bugs fixed (https://bugzilla.redhat.com/):

 

1177260 - CVE-2014-9419 kernel: partial ASLR bypass through TLS base addresses leak

1185469 - CVE-2013-7421 Linux kernel: crypto api unprivileged arbitrary module load via request_module()

1190546 - CVE-2014-9644 Linux kernel: crypto api unprivileged arbitrary module load via request_module()

1198109 - CVE-2014-8171 kernel: memcg: OOM handling DoS

1209190 - kernel-rt: rebase tree to match RHEL7.1.z source tree

1209367 - CVE-2015-2925 Kernel: vfs: Do not allow escaping from bind mounts

1211724 - kernel-rt: rebase to the RHEL7.1.z batch3 source tree

1214030 - CVE-2015-3339 kernel: race condition between chown() and execve()

1218879 - CVE-2015-4170 kernel: pty layer race condition on tty ldisc shutdown.

1230391 - kernel-rt: update to the RHEL7.1.z batch 4 source tree

1230395 - kernel-rt: update to the RHEL7.1.z batch 5 source tree

1257528 - CVE-2015-5283 kernel: Creating multiple sockets when SCTP module isn't loaded leads to kernel panic

1265251 - kernel-rt: update to the RHEL7.1.z batch 6 source tree

1268270 - CVE-2015-7613 kernel: Unauthorized access to IPC objects with SysV shm

1272472 - CVE-2015-7837 kernel: securelevel disabled after kexec

 

6. Package List:

 

Red Hat Enterprise Linux for Real Time (v. 7):

 

Source:

kernel-rt-3.10.0-327.rt56.204.el7.src.rpm

 

noarch:

kernel-rt-doc-3.10.0-327.rt56.204.el7.noarch.rpm

 

x86_64:

kernel-rt-3.10.0-327.rt56.204.el7.x86_64.rpm

kernel-rt-debug-3.10.0-327.rt56.204.el7.x86_64.rpm

kernel-rt-debug-debuginfo-3.10.0-327.rt56.204.el7.x86_64.rpm

kernel-rt-debug-devel-3.10.0-327.rt56.204.el7.x86_64.rpm

kernel-rt-debuginfo-3.10.0-327.rt56.204.el7.x86_64.rpm

kernel-rt-debuginfo-common-x86_64-3.10.0-327.rt56.204.el7.x86_64.rpm

kernel-rt-devel-3.10.0-327.rt56.204.el7.x86_64.rpm

kernel-rt-trace-3.10.0-327.rt56.204.el7.x86_64.rpm

kernel-rt-trace-debuginfo-3.10.0-327.rt56.204.el7.x86_64.rpm

kernel-rt-trace-devel-3.10.0-327.rt56.204.el7.x86_64.rpm

 

These packages are GPG signed by Red Hat for security. Our key and

details on how to verify the signature are available from

https://access.redhat.com/security/team/key/

 

7. References:

 

https://access.redhat.com/security/cve/CVE-2013-7421

https://access.redhat.com/security/cve/CVE-2014-8171

https://access.redhat.com/security/cve/CVE-2014-9419

https://access.redhat.com/security/cve/CVE-2014-9644

https://access.redhat.com/security/cve/CVE-2015-2925

https://access.redhat.com/security/cve/CVE-2015-3339

https://access.redhat.com/security/cve/CVE-2015-4170

https://access.redhat.com/security/cve/CVE-2015-5283

https://access.redhat.com/security/cve/CVE-2015-7613

https://access.redhat.com/security/cve/CVE-2015-7837

https://access.redhat.com/security/updates/classification/#important

https://access.redhat.com/articles/2055783

 

8. Contact:

 

The Red Hat security contact is . More contact

details at https://access.redhat.com/security/team/contact/

 

Copyright 2015 Red Hat, Inc.

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