Issued:

2015-11-19

Updated:

2015-11-19

RHSA-2015:2152 - Important: kernel security, bug fix, and enhancement update

Synopsis

Important: kernel security, bug fix, and enhancement update

Type/Severity

Security Advisory Important

Topic

Updated kernel packages that fix multiple security issues, address several hundred bugs, and add numerous enhancements are now available as part of the ongoing support and maintenance of Red Hat Enterprise Linux version 7. This is the second regular update.

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 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 reporting emulation failures to user space could lead to either a local (CVE-2014-7842) or a L2->L1 (CVE-2010-5313) denial of service. In the case of a local denial of service, an attacker must have access to the MMIO area or be able to access an I/O port. (CVE-2010-5313, CVE-2014-7842, Moderate)

• A flaw was found in the way the Linux kernel's KVM subsystem handled non-canonical addresses when emulating instructions that change the RIP (for example, branches or calls). A guest user with access to an I/O or MMIO region could use this flaw to crash the guest. (CVE-2014-3647, Moderate)

• 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 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. 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. (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 perf subsystem retrieved userlevel stack traces on PowerPC systems. A local, unprivileged user could use this flaw to cause a denial of service on the system. (CVE-2015-6526, 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)

• It was found that the Linux kernel KVM subsystem's sysenter instruction emulation was not sufficient. An unprivileged guest user could use this flaw to escalate their privileges by tricking the hypervisor to emulate a SYSENTER instruction in 16-bit mode, if the guest OS did not initialize the SYSENTER model-specific registers (MSRs). Note: Certified guest operating systems for Red Hat Enterprise Linux with KVM do initialize the SYSENTER MSRs and are thus not vulnerable to this issue when running on a KVM hypervisor. (CVE-2015-0239, 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)

Solution

Red Hat would like to thank Nadav Amit for reporting the CVE-2010-5313, CVE-2014-3647, CVE-2014-7842, and CVE-2015-0239 issues; and 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.

This update fixes several hundred bugs and adds numerous enhancements. Refer to the Red Hat Enterprise Linux 7.2 Release Notes for information on the most significant of these changes, and the following Knowledge base article for further information:

https://access.redhat.com/articles/1749293

All Red Hat Enterprise Linux 7 users are advised to install these updated packages, which correct these issues and add these enhancements. The system must be rebooted for this update to take effect.

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

Updated Packages

• kernel-abi-whitelists-3.10.0-327.el7.noarch.rpm
• kernel-debuginfo-common-x86_64-3.10.0-327.el7.x86_64.rpm
• kernel-tools-libs-3.10.0-327.el7.ppc64le.rpm
• kernel-tools-libs-devel-3.10.0-327.el7.ppc64.rpm
• python-perf-3.10.0-327.el7.ppc64le.rpm
• perf-debuginfo-3.10.0-327.el7.ppc64le.rpm
• kernel-3.10.0-327.el7.ppc64le.rpm
• kernel-debuginfo-common-s390x-3.10.0-327.el7.s390x.rpm
• kernel-devel-3.10.0-327.el7.ppc64.rpm
• kernel-tools-libs-devel-3.10.0-327.el7.x86_64.rpm
• kernel-devel-3.10.0-327.el7.x86_64.rpm
• python-perf-debuginfo-3.10.0-327.el7.x86_64.rpm
• kernel-3.10.0-327.el7.ppc64.rpm
• perf-3.10.0-327.el7.ppc64.rpm
• python-perf-3.10.0-327.el7.x86_64.rpm
• kernel-devel-3.10.0-327.el7.ppc64le.rpm
• perf-3.10.0-327.el7.ppc64le.rpm
• kernel-debug-debuginfo-3.10.0-327.el7.ppc64.rpm
• kernel-doc-3.10.0-327.el7.noarch.rpm
• python-perf-debuginfo-3.10.0-327.el7.s390x.rpm
• kernel-debug-debuginfo-3.10.0-327.el7.x86_64.rpm
• kernel-devel-3.10.0-327.el7.s390x.rpm
• kernel-debug-devel-3.10.0-327.el7.ppc64le.rpm
• kernel-tools-libs-3.10.0-327.el7.x86_64.rpm
• kernel-kdump-3.10.0-327.el7.s390x.rpm
• kernel-headers-3.10.0-327.el7.s390x.rpm
• kernel-debug-debuginfo-3.10.0-327.el7.s390x.rpm
• kernel-tools-libs-devel-3.10.0-327.el7.ppc64le.rpm
• kernel-debug-devel-3.10.0-327.el7.x86_64.rpm
• python-perf-3.10.0-327.el7.s390x.rpm
• kernel-3.10.0-327.el7.src.rpm
• kernel-tools-debuginfo-3.10.0-327.el7.x86_64.rpm
• kernel-debug-3.10.0-327.el7.ppc64le.rpm
• kernel-debuginfo-3.10.0-327.el7.ppc64le.rpm
• kernel-tools-libs-3.10.0-327.el7.ppc64.rpm
• kernel-debuginfo-common-ppc64-3.10.0-327.el7.ppc64.rpm
• kernel-3.10.0-327.el7.x86_64.rpm
• kernel-debug-3.10.0-327.el7.x86_64.rpm
• python-perf-debuginfo-3.10.0-327.el7.ppc64le.rpm
• kernel-tools-3.10.0-327.el7.x86_64.rpm
• perf-debuginfo-3.10.0-327.el7.s390x.rpm
• kernel-3.10.0-327.el7.s390x.rpm
• perf-debuginfo-3.10.0-327.el7.x86_64.rpm
• kernel-debuginfo-3.10.0-327.el7.s390x.rpm
• python-perf-3.10.0-327.el7.ppc64.rpm
• kernel-headers-3.10.0-327.el7.ppc64le.rpm
• kernel-debug-devel-3.10.0-327.el7.ppc64.rpm
• kernel-debuginfo-3.10.0-327.el7.x86_64.rpm
• kernel-debuginfo-3.10.0-327.el7.ppc64.rpm
• kernel-debug-3.10.0-327.el7.s390x.rpm
• kernel-tools-3.10.0-327.el7.ppc64.rpm
• kernel-bootwrapper-3.10.0-327.el7.ppc64.rpm
• kernel-bootwrapper-3.10.0-327.el7.ppc64le.rpm
• kernel-tools-debuginfo-3.10.0-327.el7.ppc64.rpm
• perf-3.10.0-327.el7.s390x.rpm
• kernel-debug-devel-3.10.0-327.el7.s390x.rpm
• kernel-kdump-debuginfo-3.10.0-327.el7.s390x.rpm
• perf-debuginfo-3.10.0-327.el7.ppc64.rpm
• kernel-kdump-devel-3.10.0-327.el7.s390x.rpm
• kernel-headers-3.10.0-327.el7.ppc64.rpm
• kernel-debuginfo-common-ppc64le-3.10.0-327.el7.ppc64le.rpm
• kernel-debug-debuginfo-3.10.0-327.el7.ppc64le.rpm
• kernel-headers-3.10.0-327.el7.x86_64.rpm
• perf-3.10.0-327.el7.x86_64.rpm
• python-perf-debuginfo-3.10.0-327.el7.ppc64.rpm
• kernel-debug-3.10.0-327.el7.ppc64.rpm
• kernel-tools-debuginfo-3.10.0-327.el7.ppc64le.rpm
• kernel-tools-3.10.0-327.el7.ppc64le.rpm

Fixes

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• This content is not included.BZ - 1076738
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• This content is not included.BZ - 1144897
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• This content is not included.BZ - 1251331
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• This content is not included.BZ - 1272472

CVEs

• CVE-2010-5313
• CVE-2013-7421
• CVE-2014-3647
• CVE-2014-7842
• CVE-2014-8171
• CVE-2014-9419
• CVE-2014-9644
• CVE-2015-0239
• CVE-2015-2925
• CVE-2015-3288
• CVE-2015-3339
• CVE-2015-4170
• CVE-2015-5283
• CVE-2015-6526
• CVE-2015-7553
• CVE-2015-7613
• CVE-2015-7837
• CVE-2015-8215
• CVE-2016-0774

References

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

Additional information

• The Red Hat security contact is This content is not included.secalert@redhat.com. More contact details at https://access.redhat.com/security/team/contact/.
• Offline Security Data data is available for integration with other systems. See Offline Security Data API to get started.