RHSA-2016:1847 - Security Advisory

Topic

An update for kernel is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

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

Security Fix(es):

• A security flaw was found in the Linux kernel in the mark_source_chains() function in "net/ipv4/netfilter/ip_tables.c". It is possible for a user-supplied "ipt_entry" structure to have a large "next_offset" field. This field is not bounds checked prior to writing to a counter value at the supplied offset. (CVE-2016-3134, Important)
• A flaw was discovered in processing setsockopt for 32 bit processes on 64 bit systems. This flaw will allow attackers to alter arbitrary kernel memory when unloading a kernel module. This action is usually restricted to root-privileged users but can also be leveraged if the kernel is compiled with CONFIG_USER_NS and CONFIG_NET_NS and the user is granted elevated privileges. (CVE-2016-4997, Important)
• An out-of-bounds heap memory access leading to a Denial of Service, heap disclosure, or further impact was found in setsockopt(). The function call is normally restricted to root, however some processes with cap_sys_admin may also be able to trigger this flaw in privileged container environments. (CVE-2016-4998, Moderate)

Bug Fix(es):

• In some cases, running the ipmitool command caused a kernel panic due to a race condition in the ipmi message handler. This update fixes the race condition, and the kernel panic no longer occurs in the described scenario. (BZ#1353947)
• Previously, running I/O-intensive operations in some cases caused the system to terminate unexpectedly after a null pointer dereference in the kernel. With this update, a set of patches has been applied to the 3w-9xxx and 3w-sas drivers that fix this bug. As a result, the system no longer crashes in the described scenario. (BZ#1362040)
• Previously, the Stream Control Transmission Protocol (SCTP) sockets did not inherit the SELinux labels properly. As a consequence, the sockets were labeled with the unlabeled_t SELinux type which caused SCTP connections to fail. The underlying source code has been modified, and SCTP connections now works as expected. (BZ#1354302)
• Previously, the bnx2x driver waited for transmission completions when recovering from a parity event, which substantially increased the recovery time. With this update, bnx2x does not wait for transmission completion in the described circumstances. As a result, the recovery of bnx2x after a parity event now takes less time. (BZ#1351972)

Enhancement(s):

• With this update, the audit subsystem enables filtering of processes by name besides filtering by PID. Users can now audit by executable name (with the "-F exe=<path-to-executable>" option), which allows expression of many new audit rules. This functionality can be used to create events when specific applications perform a syscall. (BZ#1345774)
• With this update, the Nonvolatile Memory Express (NVMe) and the multi-queue block layer (blk_mq) have been upgraded to the Linux 4.5 upstream version. Previously, a race condition between timeout and freeing request in blk_mq occurred, which could affect the blk_mq_tag_to_rq() function and consequently a kernel oops could occur. The provided patch fixes this race condition by updating the tags with the active request. The patch simplifies blk_mq_tag_to_rq() and ensures that the two requests are not active at the same time. (BZ#1350352)
• The Hyper-V storage driver (storvsc) has been upgraded from upstream. This update provides moderate performance improvement of I/O operations when using storvscr for certain workloads. (BZ#1360161)

Additional Changes:

Space precludes documenting all of the bug fixes and enhancements included in this advisory. To see the complete list of bug fixes and enhancements, refer to the following KnowledgeBase article: https://access.redhat.com/articles/2592321

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

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

The system must be rebooted for this update to take effect.

Affected Products

• Red Hat Enterprise Linux Server 7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.5 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.3 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.2 x86_64
• Red Hat Enterprise Linux Server - AUS 7.7 x86_64
• Red Hat Enterprise Linux Server - AUS 7.6 x86_64
• Red Hat Enterprise Linux Server - AUS 7.4 x86_64
• Red Hat Enterprise Linux Server - AUS 7.3 x86_64
• Red Hat Enterprise Linux Server - AUS 7.2 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 7 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64
• Red Hat Enterprise Linux Desktop 7 x86_64
• Red Hat Enterprise Linux for IBM z Systems 7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.5 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.4 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.3 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.2 s390x
• Red Hat Enterprise Linux for Power, big endian 7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.5 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.4 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.3 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.2 ppc64
• Red Hat Enterprise Linux for Scientific Computing 7 x86_64
• Red Hat Enterprise Linux for Power, little endian 7 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.7 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.6 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.5 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.4 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.3 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.2 ppc64le
• Red Hat Enterprise Linux Server - TUS 7.7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.6 x86_64
• Red Hat Enterprise Linux Server - TUS 7.3 x86_64
• Red Hat Enterprise Linux Server - TUS 7.2 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 7 s390x
• Red Hat Enterprise Linux EUS Compute Node 7.7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.6 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.5 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.4 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.3 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.2 x86_64
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 7.7 ppc64le
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 7.6 ppc64le
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 7.4 ppc64le
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 7.3 ppc64le
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.3 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.2 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, big endian 7 ppc64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, little endian 7 ppc64le

Fixes

• BZ - 1317383 - CVE-2016-3134 kernel: netfilter: missing bounds check in ipt_entry structure
• BZ - 1349722 - CVE-2016-4997 kernel: compat IPT_SO_SET_REPLACE setsockopt
• BZ - 1349886 - CVE-2016-4998 kernel: out of bounds reads when processing IPT_SO_SET_REPLACE setsockopt

CVEs

• CVE-2016-3134
• CVE-2016-4997
• CVE-2016-4998
• CVE-2016-6197
• CVE-2016-6198

References

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