10 - RHSA-2015:0864

Problem Description:

Updated kernel packages that fix multiple security issues and several bugs are now available for Red Hat Enterprise Linux 6.

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 Desktop (v. 6) - i386, noarch, x86_64 Red Hat Enterprise Linux Desktop Optional (v. 6) - i386, x86_64 Red Hat Enterprise Linux HPC Node (v. 6) - noarch, x86_64 Red Hat Enterprise Linux HPC Node Optional (v. 6) - x86_64 Red Hat Enterprise Linux Server (v. 6) - i386, noarch, ppc64, s390x, x86_64 Red Hat Enterprise Linux Server Optional (v. 6) - i386, ppc64, s390x, x86_64 Red Hat Enterprise Linux Workstation (v. 6) - i386, noarch, x86_64 Red Hat Enterprise Linux Workstation Optional (v. 6) - i386, x86_64

3. Description:

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

* A flaw was found in the way seunshare, a utility for running executables under a different security context, used the capng_lock functionality of the libcap-ng library. The subsequent invocation of suid root binaries that relied on the fact that the setuid() system call, among others, also sets the saved set-user-ID when dropping the binaries' process privileges, could allow a local, unprivileged user to potentially escalate their privileges on the system. Note: the fix for this issue is the kernel part of the overall fix, and introduces the PR_SET_NO_NEW_PRIVS functionality and the related SELinux exec transitions support. (CVE-2014-3215, Important)

* A use-after-free flaw was found in the way the Linux kernel's SCTP implementation handled authentication key reference counting during INIT collisions. A remote attacker could use this flaw to crash the system or, potentially, escalate their privileges on the system. (CVE-2015-1421, Important)

* It was found that the Linux kernel's KVM implementation did not ensure that the host CR4 control register value remained unchanged across VM entries on the same virtual CPU. A local, unprivileged user could use this flaw to cause a denial of service on the system. (CVE-2014-3690, Moderate)

* An out-of-bounds memory access flaw was found in the syscall tracing functionality of the Linux kernel's perf subsystem. A local, unprivileged user could use this flaw to crash the system. (CVE-2014-7825, Moderate)

* An out-of-bounds memory access flaw was found in the syscall tracing functionality of the Linux kernel's ftrace subsystem. On a system with ftrace syscall tracing enabled, a local, unprivileged user could use this flaw to crash the system, or escalate their privileges. (CVE-2014-7826, 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 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 in the way the Linux kernel keys management subsystem performed key garbage collection. A local attacker could attempt accessing a key while it was being garbage collected, which would cause the system to crash. (CVE-2014-9529, Moderate)

* A stack-based buffer overflow flaw was found in the TechnoTrend/Hauppauge DEC USB device driver. A local user with write access to the corresponding device could use this flaw to crash the kernel or, potentially, elevate their privileges on the system. (CVE-2014-8884, Low)

* An information leak flaw was found in the way the Linux kernel's ISO9660 file system implementation accessed data on an ISO9660 image with RockRidge Extension Reference (ER) records. An attacker with physical access to the system could use this flaw to disclose up to 255 bytes of kernel memory. (CVE-2014-9584, Low)

Red Hat would like to thank Andy Lutomirski for reporting CVE-2014-3215 and CVE-2014-3690, Robert Święcki for reporting CVE-2014-7825 and CVE-2014-7826, and Carl Henrik Lunde for reporting CVE-2014-9584. The CVE-2015-1421 issue was discovered by Sun Baoliang of Red Hat.

This update also fixes several bugs. 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. 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/):

1095855 - CVE-2014-3215 policycoreutils: local privilege escalation via seunshare 1153322 - CVE-2014-3690 kernel: kvm: vmx: invalid host cr4 handling across vm entries 1161565 - CVE-2014-7825 CVE-2014-7826 kernel: insufficient syscall number validation in perf and ftrace subsystems 1164266 - CVE-2014-8884 kernel: usb: buffer overflow in ttusb-dec 1179813 - CVE-2014-9529 kernel: memory corruption or panic during key garbage collection 1180119 - CVE-2014-9584 kernel: isofs: unchecked printing of ER records 1196581 - CVE-2015-1421 kernel: net: slab corruption from use after free on INIT collisions 1198109 - CVE-2014-8171 kernel: memcg: OOM handling DoS