7.2 - RHSA-2015:0674

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.

* It was found that the Linux kernel's Infiniband subsystem did not properly sanitize input parameters while registering memory regions from user space via the (u)verbs API. A local user with access to a /dev/infiniband/uverbsX device could use this flaw to crash the system or, potentially, escalate their privileges on the system. (CVE-2014-8159, Important)

* A flaw was found in the way the Linux kernel's splice() system call validated its parameters. On certain file systems, a local, unprivileged user could use this flaw to write past the maximum file size, and thus crash the system. (CVE-2014-7822, Moderate)

* A flaw was found in the way the Linux kernel's netfilter subsystem handled generic protocol tracking. As demonstrated in the Stream Control Transmission Protocol (SCTP) case, a remote attacker could use this flaw to bypass intended iptables rule restrictions when the associated connection tracking module was not loaded on the system. (CVE-2014-8160, Moderate)

* It was found that the fix for CVE-2014-3601 was incomplete: the Linux kernel's kvm_iommu_map_pages() function still handled IOMMU mapping failures incorrectly. A privileged user in a guest with an assigned host device could use this flaw to crash the host. (CVE-2014-8369, Moderate)

Red Hat would like to thank Mellanox for reporting CVE-2014-8159, and Akira Fujita of NEC for reporting CVE-2014-7822.

Bug fixes:

* The maximum amount of entries in the IPv6 route table (net.ipv6.route.max_size) was 4096, and every route towards this maximum size limit was counted. Communication to more systems was impossible when the limit was exceeded. Now, only cached routes are counted, which guarantees that the kernel does not run out of memory, but the user can now install as many routes as the memory allows until the kernel indicates it can no longer handle the amount of memory and returns an error message.

In addition, the default "net.ipv6.route.max_size" value has been increased to 16384 for performance improvement reasons. (BZ#1177581)

* When the user attempted to scan for an FCOE-served Logical Unit Number (LUN), after an initial LUN scan, a kernel panic occurred in bnx2fc_init_task. System scanning for LUNs is now stable after LUNs have been added. (BZ#1179098)

* Under certain conditions, such as when attempting to scan the network for LUNs, a race condition in the bnx2fc driver could trigger a kernel panic in bnx2fc_init_task. A patch fixing a locking issue that caused the race condition has been applied, and scanning the network for LUNs no longer leads to a kernel panic. (BZ#1179098)

* Previously, it was not possible to boot the kernel on Xen hypervisor in PVHVM mode if more than 32 vCPUs were specified in the guest configuration. Support for more than 32 vCPUs has been added, and the kernel now boots successfully in the described situation. (BZ#1179343)

* When the NVMe driver allocated a namespace queue, it indicated that it was a request-based driver when it was actually a block I/O-based driver. Consequently, when NVMe driver was loaded along with a request-based dm device, the system could terminate unexpectedly or become unresponsive when attempting to access data. The NVMe driver no longer sets the QUEUE_FLAG_STACKABLE bit when allocating a namespace queue and device-mapper no longer perceives NVMe driver as request-based; system hangs or crashes no longer occur. (BZ#1180555)

* If a user attempted to apply an NVRAM firmware update when running the tg3 module provided with Red Hat Enterprise Linux 6.6 kernels, the update could fail. As a consequence, the Network Interface Card (NIC) could stay in an unusable state and this could prevent the entire system from booting. The tg3 module has been updated to correctly apply firmware updates. (BZ#1182903)

* Support for key sizes of 256 and 192 bits has been added to AES-NI. (BZ#1184332)

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.

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258

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

1156518 - CVE-2014-8369 kernel: kvm: excessive pages un-pinning in kvm_iommu_map error path 1163792 - CVE-2014-7822 kernel: splice: lack of generic write checks 1181166 - CVE-2014-8159 kernel: infiniband: uverbs: unprotected physical memory access 1182059 - CVE-2014-8160 kernel: iptables restriction bypass if a protocol handler kernel module not loaded