kernel (SL7)

Synopsis: Important: kernel security, bug fix, and enhancement update
Advisory ID: SLSA-2016:1847-1
Issue Date: 2016-09-15
CVE Numbers: CVE-2016-3134

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

* 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.

* 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.

* 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.


* 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=” option), which allows expression
of many new audit rules. This functionality can be used to create events
when specific applications perform a syscall.

* 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.

* 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.


– Scientific Linux Development Team