RHEL 6 : kernel (RHSA-2013:1450)
Medium Nessus Plugin ID 78974
SynopsisThe remote Red Hat host is missing one or more security updates.
DescriptionUpdated kernel packages that fix three security issues and several bugs are now available for Red Hat Enterprise Linux 6.3 Extended Update Support.
The Red Hat Security Response Team 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.
* It was found that the fix for CVE-2012-3552 released via RHSA-2012:1540 introduced an invalid free flaw in the Linux kernel's TCP/IP protocol suite implementation. A local, unprivileged user could use this flaw to corrupt kernel memory via crafted sendmsg() calls, allowing them to cause a denial of service or, potentially, escalate their privileges on the system. (CVE-2013-2224, Important)
* An information leak flaw was found in the way Linux kernel's device mapper subsystem, under certain conditions, interpreted data written to snapshot block devices. An attacker could use this flaw to read data from disk blocks in free space, which are normally inaccessible.
* A format string flaw was found in the b43_do_request_fw() function in the Linux kernel's b43 driver implementation. A local user who is able to specify the 'fwpostfix' b43 module parameter could use this flaw to cause a denial of service or, potentially, escalate their privileges. (CVE-2013-2852, Low)
Red Hat would like to thank Fujitsu for reporting CVE-2013-4299, and Kees Cook for reporting CVE-2013-2852.
This update also fixes the following bugs :
* An insufficiently designed calculation in the CPU accelerator could cause an arithmetic overflow in the set_cyc2ns_scale() function if the system uptime exceeded 208 days prior to using kexec to boot into a new kernel. This overflow led to a kernel panic on the systems using the Time Stamp Counter (TSC) clock source, primarily the systems using Intel Xeon E5 processors that do not reset TSC on soft power cycles. A patch has been applied to modify the calculation so that this arithmetic overflow and kernel panic can no longer occur under these circumstances. (BZ#1004185)
* A race condition in the abort task and SPP device task management path of the isci driver could, under certain circumstances, cause the driver to fail cleaning up timed-out I/O requests that were pending on an SAS disk device. As a consequence, the kernel removed such a device from the system. A patch applied to the isci driver fixes this problem by sending the task management function request to the SAS drive anytime the abort function is entered and the task has not completed.
The driver now cleans up timed-out I/O requests as expected in this situation. (BZ#1007467)
* A kernel panic could occur during path failover on systems using multiple iSCSI, FC or SRP paths to connect an iSCSI initiator and an iSCSI target. This happened because a race condition in the SCSI driver allowed removing a SCSI device from the system before processing its run queue, which led to a NULL pointer dereference. The SCSI driver has been modified and the race is now avoided by holding a reference to a SCSI device run queue while it is active. (BZ#1008507)
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.
SolutionUpdate the affected packages.