RHEL 6 : kernel-rt (RHSA-2015:0751)
Critical Nessus Plugin ID 82467
SynopsisThe remote Red Hat host is missing one or more security updates.
DescriptionUpdated kernel-rt packages that fix two security issues and several bugs are now available for Red Hat Enterprise MRG 2.5.
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-rt 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.
* A use-after-free flaw was found in the way the Linux kernel's SCTP implementation handled authentication key reference counting during INIT collisions. A remote attacker could use this flaw to crash the system or, potentially, escalate their privileges on the system.
Red Hat would like to thank Mellanox for reporting the CVE-2014-8159 issue. The CVE-2015-1421 issue was discovered by Sun Baoliang of Red Hat.
The MRG-Realtime 3.10 kernel-rt sources have been updated to include the following bug fixes :
* The kdump service could become unresponsive due to a deadlock in the kernel call ioapic_lock.
* Attempt to make metadata changes such as creating a thin device or snapshot thin device did not error out cleanly.
This update also fixes the following bug :
* The MRG kernel scheduler code was missing checks for the PREEMPT_LAZY flag allowing tasks to be preempted more times than necessary causing latency spikes on the system. Additional checks for the PREEMPT_LAZY flag were added to the check_preempt_wakeup() and check_preempt_curr() functions in the scheduler code so that preempt wakeups were reduced and these latency spikes were removed.
All kernel-rt users are advised to upgrade to these updated packages, which correct these issues. The system must be rebooted for this update to take effect.
SolutionUpdate the affected packages.