RHSA-2015:1787: Important: kernel-rt security, bug fix, and enhancement update

The kernel-rt packages contain the Linux kernel, the core of any Linuxoperating system. Two flaws were found in the way the Linux kernel's networking implementation handled UDP packets with incorrect checksum values. A remoteattacker could potentially use these flaws to trigger an infinite loop inthe kernel, resulting in a denial of service on the system, or cause adenial of service in applications using the edge triggered epollfunctionality. (CVE-2015-5364, CVE-2015-5366, Important) A flaw was found in the way the Linux kernel's ext4 file system handled the "page size > block size" condition when the fallocate zero rangefunctionality was used. A local attacker could use this flaw to crash thesystem. (CVE-2015-0275, Moderate) It was found that the Linux kernel's keyring implementation would leak memory when adding a key to a keyring via the addkey() function. A localattacker could use this flaw to exhaust all available memory on the system.(CVE-2015-1333, Moderate) A race condition flaw was found in the way the Linux kernel's SCTP implementation handled Address Configuration lists when performing AddressConfiguration Change (ASCONF). A local attacker could use this flaw tocrash the system via a race condition triggered by setting certain ASCONFoptions on a socket. (CVE-2015-3212, Moderate) An information leak flaw was found in the way the Linux kernel's Virtual Dynamic Shared Object (vDSO) implementation performed addressrandomization. A local, unprivileged user could use this flaw to leakkernel memory addresses to user-space. (CVE-2014-9585, Low)Red Hat would like to thank Canonical for reporting the CVE-2015-1333issue. The CVE-2015-0275 issue was discovered by Xiong Zhou of Red Hat, andthe CVE-2015-3212 issue was discovered by Ji Jianwen of Red HatEngineering.This update provides a build of the kernel-rt package for Red HatEnterprise MRG 2.5 that is layered on Red Hat Enterprise Linux 6, and fixesthe following issues: Fix regression in scsisendehcmnd() boot hangs at "Console: switching to colour dummy device 80x25" Update tcp stack to 3.17 kernel ksoftirqd high CPU usage due to stray tasklet from ioatdma driver (BZ#1245345)This update also fixes the following bugs: The configuration option CONFIGRTCHCTOSYS was disabled on the realtime kernel causing the RTC clock to be adjusted with the UTC time even if thesystem is configured to set the RTC to the local time. By enabling theCONFIGRTCHCTOSYS configuration option, when the system is configured touse local time, RTC will correctly update with the local time and not tryto use another timezone. (BZ#1248047) In the realtime kernel, if a rtmutex was taken while in interrupt context the normal priority inheritance protocol would falsely identify adeadlock and trigger a kernel crash. The patch that added the rtmutex inthis interrupt context was reverted. (BZ#1250649)All kernel-rt users are advised to upgrade to these updated packages, whichcorrect these issues and add these enhancements. The system must berebooted for this update to take effect.