7.8 - RHSA-2014:1997

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.

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

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:

* A flaw was found in the way the Linux kernel handled GS segment register base switching when recovering from a #SS (stack segment) fault on an erroneous return to user space. A local, unprivileged user could use this flaw to escalate their privileges on the system. (CVE-2014-9322, Important)

* A flaw was found in the way the Linux kernel's SCTP implementation handled malformed or duplicate Address Configuration Change Chunks (ASCONF). A remote attacker could use either of these flaws to crash the system. (CVE-2014-3673, CVE-2014-3687, Important)

* A flaw was found in the way the Linux kernel's SCTP implementation handled the association's output queue. A remote attacker could send specially crafted packets that would cause the system to use an excessive amount of memory, leading to a denial of service. (CVE-2014-3688, Important)

* A stack overflow flaw caused by infinite recursion was found in the way the Linux kernel's UDF file system implementation processed indirect ICBs. An attacker with physical access to the system could use a specially crafted UDF image to crash the system. (CVE-2014-6410, Low)

* It was found that the Linux kernel's networking implementation did not correctly handle the setting of the keepalive socket option on raw sockets. A local user able to create a raw socket could use this flaw to crash the system. (CVE-2012-6657, Low)

* It was found that the parse_rock_ridge_inode_internal() function of the Linux kernel's ISOFS implementation did not correctly check relocated directories when processing Rock Ridge child link (CL) tags. An attacker with physical access to the system could use a specially crafted ISO image to crash the system or, potentially, escalate their privileges on the system. (CVE-2014-5471, CVE-2014-5472, Low)

Red Hat would like to thank Andy Lutomirski for reporting CVE-2014-9322. The CVE-2014-3673 issue was discovered by Liu Wei of Red Hat.

Bug fixes:

* This update fixes a race condition issue between the sock_queue_err_skb function and sk_forward_alloc handling in the socket error queue (MSG_ERRQUEUE), which could occasionally cause the kernel, for example when using PTP, to incorrectly track allocated memory for the error queue, in which case a traceback would occur in the system log. (BZ#1155427)

* The zcrypt device driver did not detect certain crypto cards and the related domains for crypto adapters on System z and s390x architectures. Consequently, it was not possible to run the system on new crypto hardware. This update enables toleration mode for such devices so that the system can make use of newer crypto hardware. (BZ#1158311)

* After mounting and unmounting an XFS file system several times consecutively, the umount command occasionally became unresponsive. This was caused by the xlog_cil_force_lsn() function that was not waiting for completion as expected. With this update, xlog_cil_force_lsn() has been modified to correctly wait for completion, thus fixing this bug. (BZ#1158325)

* When using the ixgbe adapter with disabled LRO and the tx-usec or rs-usec variables set to 0, transmit interrupts could not be set lower than the default of 8 buffered tx frames. Consequently, a delay of TCP transfer occurred. The restriction of a minimum of 8 buffered frames has been removed, and the TCP delay no longer occurs. (BZ#1158326)

* The offb driver has been updated for the QEMU standard VGA adapter, fixing an incorrect displaying of colors issue. (BZ#1158328)

* Under certain circumstances, when a discovered MTU expired, the IPv6 connection became unavailable for a short period of time. This bug has been fixed, and the connection now works as expected. (BZ#1161418)

* A low throughput occurred when using the dm-thin driver to write to unprovisioned or shared chunks for a thin pool with the chunk size bigger than the max_sectors_kb variable. (BZ#1161420)

* Large write workloads on thin LVs could cause the iozone and smallfile utilities to terminate unexpectedly. (BZ#1161421)

4. Solution:

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.

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/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/):

1134099 - CVE-2014-5471 CVE-2014-5472 kernel: isofs: unbound recursion when processing relocated directories 1141742 - CVE-2012-6657 Kernel: net: guard tcp_set_keepalive against crash 1141809 - CVE-2014-6410 kernel: udf: Avoid infinite loop when processing indirect ICBs 1147850 - CVE-2014-3673 kernel: sctp: skb_over_panic when receiving malformed ASCONF chunks 1155731 - CVE-2014-3687 kernel: net: sctp: fix panic on duplicate ASCONF chunks 1155745 - CVE-2014-3688 kernel: net: sctp: remote memory pressure from excessive queueing 1172806 - CVE-2014-9322 kernel: x86: local privesc due to bad_iret and paranoid entry incompatibility