7.2 - RHSA-2014:0913

Problem Description:

Updated kernel-rt packages that fix multiple security issues are now available for Red Hat Enterprise MRG 2.5.

The Red Hat Security Response Team 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:

MRG Realtime for RHEL 6 Server v.2 - 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 futex subsystem handled the requeuing of certain Priority Inheritance (PI) futexes. A local, unprivileged user could use this flaw to escalate their privileges on the system. (CVE-2014-3153, Important)

* It was found that the Linux kernel's ptrace subsystem allowed a traced process' instruction pointer to be set to a non-canonical memory address without forcing the non-sysret code path when returning to user space. A local, unprivileged user could use this flaw to crash the system or, potentially, escalate their privileges on the system. (CVE-2014-4699, Important)

Note: The CVE-2014-4699 issue only affected systems using an Intel CPU.

* It was found that the permission checks performed by the Linux kernel when a netlink message was received were not sufficient. A local, unprivileged user could potentially bypass these restrictions by passing a netlink socket as stdout or stderr to a more privileged process and altering the output of this process. (CVE-2014-0181, Moderate)

* It was found that the aio_read_events_ring() function of the Linux kernel's Asynchronous I/O (AIO) subsystem did not properly sanitize the AIO ring head received from user space. A local, unprivileged user could use this flaw to disclose random parts of the (physical) memory belonging to the kernel and/or other processes. (CVE-2014-0206, Moderate)

* An out-of-bounds memory access flaw was found in the Netlink Attribute extension of the Berkeley Packet Filter (BPF) interpreter functionality in the Linux kernel's networking implementation. A local, unprivileged user could use this flaw to crash the system or leak kernel memory to user space via a specially crafted socket filter. (CVE-2014-3144, CVE-2014-3145, Moderate)

* An out-of-bounds memory access flaw was found in the Linux kernel's system call auditing implementation. On a system with existing audit rules defined, a local, unprivileged user could use this flaw to leak kernel memory to user space or, potentially, crash the system. (CVE-2014-3917, Moderate)

* A flaw was found in the way Linux kernel's Transparent Huge Pages (THP) implementation handled non-huge page migration. A local, unprivileged user could use this flaw to crash the kernel by migrating transparent hugepages. (CVE-2014-3940, Moderate)

* An integer underflow flaw was found in the way the Linux kernel's Stream Control Transmission Protocol (SCTP) implementation processed certain COOKIE_ECHO packets. By sending a specially crafted SCTP packet, a remote attacker could use this flaw to prevent legitimate connections to a particular SCTP server socket to be made. (CVE-2014-4667, Moderate)

* An information leak flaw was found in the RAM Disks Memory Copy (rd_mcp) backend driver of the iSCSI Target subsystem of the Linux kernel. A privileged user could use this flaw to leak the contents of kernel memory to an iSCSI initiator remote client. (CVE-2014-4027, Low)

Red Hat would like to thank Kees Cook of Google for reporting CVE-2014-3153, Andy Lutomirski for reporting CVE-2014-4699 and CVE-2014-0181, and Gopal Reddy Kodudula of Nokia Siemens Networks for reporting CVE-2014-4667. Google acknowledges Pinkie Pie as the original reporter of CVE-2014-3153. The CVE-2014-0206 issue was discovered by Mateusz Guzik of Red Hat.

Users are advised to upgrade to these updated packages, which upgrade the kernel-rt kernel to version kernel-rt-3.10.33-rt32.43 and 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.

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/site/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.

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

1094265 - CVE-2014-0181 kernel: net: insufficient permision checks of netlink messages 1094602 - CVE-2014-0206 kernel: aio: insufficient sanitization of head in aio_read_events_ring() 1096775 - CVE-2014-3144 CVE-2014-3145 Kernel: filter: prevent nla extensions to peek beyond the end of the message 1102571 - CVE-2014-3917 kernel: DoS with syscall auditing 1103626 - CVE-2014-3153 kernel: futex: pi futexes requeue issue 1104097 - CVE-2014-3940 Kernel: missing check during hugepage migration 1108744 - CVE-2014-4027 Kernel: target/rd: imformation leakage 1113967 - CVE-2014-4667 kernel: sctp: sk_ack_backlog wrap-around problem 1115927 - CVE-2014-4699 kernel: x86_64: ptrace: sysret to non-canonical address