CentOS Errata and Security Advisory CESA-2014:0740
The kernel packages contain the Linux kernel, the core of any Linux operating system.
A flaw was found in the way the Linux kernel's floppy driver handled user space provided data in certain error code paths while processing FDRAWCMD IOCTL commands. A local user with write access to /dev/fdX could use this flaw to free (using the kfree() function) arbitrary kernel memory. (CVE-2014-1737, Important)
It was found that the Linux kernel's floppy driver leaked internal kernel memory addresses to user space during the processing of the FDRAWCMD IOCTL command. A local user with write access to /dev/fdX could use this flaw to obtain information about the kernel heap arrangement. (CVE-2014-1738, Low)
Note: A local user with write access to /dev/fdX could use these two flaws (CVE-2014-1737 in combination with CVE-2014-1738) to escalate their privileges on the system.
Red Hat would like to thank Matthew Daley for reporting CVE-2014-1737 and CVE-2014-1738.
This update also fixes the following bugs:
A bug in the futex system call could result in an overflow when passing a very large positive timeout. As a consequence, the FUTEX_WAIT operation did not work as intended and the system call was timing out immediately. A backported patch fixes this bug by limiting very large positive timeouts to the maximal supported value. (BZ#1091832)
A new Linux Security Module (LSM) functionality related to the setrlimit hooks should produce a warning message when used by a third party module that could not cope with it. However, due to a programming error, the kernel could print this warning message when a process was setting rlimits for a different process, or if rlimits were modified by another than the main thread even though there was no incompatible third party module. This update fixes the relevant code and ensures that the kernel handles this warning message correctly. (BZ#1092869)
Previously, the kernel was unable to detect KVM on system boot if the Hyper-V emulation was enabled. A patch has been applied to ensure that both KVM and Hyper-V hypervisors are now correctly detected during system boot. (BZ#1094152)
A function in the RPC code responsible for verifying whether cached credentials match the current process did not perform the check correctly. The code checked only whether the groups in the current process credentials appear in the same order as in the cached credentials but did not ensure that no other groups are present in the cached credentials. As a consequence, when accessing files in NFS mounts, a process with the same UID and GID as the original process but with a non-matching group list could have been granted an unauthorized access to a file, or under certain circumstances, the process could have been wrongly prevented from accessing the file. The incorrect test condition has been fixed and the problem can no longer occur. (BZ#1095062)
When being under heavy load, some Fibre Channel storage devices, such as Hitachi and HP Open-V series, can send a logout (LOGO) message to the host system. However, due to a bug in the lpfc driver, this could result in a loss of active paths to the storage and the paths could not be recovered without manual intervention. This update corrects the lpfc driver to ensure automatic recovery of the lost paths to the storage in this scenario. (BZ#1096061)
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.
Merged security bulletin from advisories: http://lists.centos.org/pipermail/centos-announce/2014-June/032401.html
Affected packages: kernel kernel-PAE kernel-PAE-devel kernel-debug kernel-debug-devel kernel-devel kernel-doc kernel-headers kernel-xen kernel-xen-devel
Upstream details at: https://rhn.redhat.com/errata/RHSA-2014-0740.html