RHSA-2010:0041: Important: kernel-rt security and bug fix update

The kernel-rt packages contain the Linux kernel, the core of any Linuxoperating system.This update fixes the following security issues: an array index error was found in the gdth driver in the Linux kernel. A local user could send a specially-crafted IOCTL request that would cause adenial of service or, possibly, privilege escalation. (CVE-2009-3080,Important) a flaw was found in the FUSE implementation in the Linux kernel. When a system is low on memory, fuseputrequest() could dereference an invalidpointer, possibly leading to a local denial of service or privilegeescalation. (CVE-2009-4021, Important) a flaw was found in each of the following Intel PRO/1000 Linux drivers in the Linux kernel: e1000 and e1000e. A remote attacker using packets largerthan the MTU could bypass the existing fragment check, resulting inpartial, invalid frames being passed to the network stack. These flawscould also possibly be used to trigger a remote denial of service.(CVE-2009-4536, CVE-2009-4538, Important) a flaw was found in the Realtek r8169 Ethernet driver in the Linux kernel. Receiving overly-long frames with a certain revision of the networkcards supported by this driver could possibly result in a remote denial ofservice. (CVE-2009-4537, Important)This update also fixes the following bugs: the "function tracer" from ftrace could eventually present problems when a module was unloaded during a tracing session. Some of the related callsite entries for that module were not removed from ftrace's internal listsand could lead to confusing "oops" error messages. The call site entriesare now removed correctly, and the errors no longer occur. (BZ#537472) when using the kernel in tickless (or NOHZ) mode, time was not accumulated one tick at a time. This created latencies when the accumulatedinterval grew large. Time is now accumulated logarithmically and latenciesrelated to tickless mode no longer occur. (BZ#538370) running the "cset set" command was resulting in unsafe access to a structure that could be concurrently changed. This was eventually causingthe kernel to crash. The operations were repositioned so that they nolonger add locks, to minimize performance penalties. (BZ#541080) the function used to calculate system load called different functions to count the tasks in running and interpretable states. On systems with alarge number of CPUs, this could result in several TLB and cache misses.These functions have now been combined, and the problem has beensignificantly reduced. (BZ#552860) when legacy PCI bus checks occurred, an off-by-one error would present. Scanning 255 PCI buses is now allowed as 0xff is a valid bus, and the errorno longer occurs. (BZ#552874) on systems with 8 or more CPUs, an unnecessary anonvma lock acquisition in vmaadjust() was causing a decrease in throughput. Code from theupstream kernel was backported, and the throughput decrease no longerexists. (BZ#552876) the scheduler function doublelockbalance() favors logically lower CPUs. This could cause logically higher CPUs to be starved if run queues wereunder a lot of pressure, resulting in latencies. The algorithm has beenadjusted so that it is fairer, and logically higher CPUs no longer riskbeing starved. (BZ#552877)These updated packages also include other bug fixes. Users are directed tothe Red Hat Enterprise MRG 1.2 Release Notes for information on thosefixes, available shortly from:http://www.redhat.com/docs/en-US/RedHatEnterpriseMRG/ Users should upgrade to these updated packages, which contain backportedpatches to correct these issues. The system must be rebooted for thisupdate to take effect.