The kernel packages contain the Linux kernel, the core of any Linux operating system. Security fixes: * RHSA-2009:1024 introduced a flaw in the ptrace implementation on Itanium systems. ptrace_check_attach was not called during certain ptrace requests. Under certain circumstances, a local, unprivileged user could use this flaw to call ptrace on a process they do not own, giving them control over that process. * a flaw was found in the kernel"s Unidirectional Lightweight Encapsulation implementation. A remote attacker could send a specially-crafted ISO MPEG-2 Transport Stream frame to a target system, resulting in a denial of service. * a use-after-free flaw was found in tcp_rcv_state_process in the kernel"s TCP/IP protocol suite implementation. If a system using IPv6 had the IPV6_RECVPKTINFO option set on a listening socket, a remote attacker could send an IPv6 packet to that system, causing a kernel panic. * a divide-by-zero flaw was found in azx_position_ok in the Intel High Definition Audio driver, snd-hda-intel. A local, unprivileged user could trigger this flaw to cause a denial of service. * an information leak flaw was found in the kernel"s USB implementation. Certain USB errors could result in an uninitialized kernel buffer being sent to user-space. An attacker with physical access to a target system could use this flaw to cause an information leak. Red Hat would like to thank Ang Way Chuang for reporting CVE-2010-1086. Bug fixes: * a regression prevented the Broadcom BCM5761 network device from working when in the first PCI-E slot of Hewlett-Packard Z600 systems. Note: The card worked in the 2nd or 3rd PCI-E slot. * the Xen hypervisor supports 168 GB of RAM for 32-bit guests. The physical address range was set incorrectly, however, causing 32-bit, para-virtualized Red Hat Enterprise Linux 4.8 guests to crash when launched on AMD64 or Intel 64 hosts that have more than 64 GB of RAM. * RHSA-2009:1024 introduced a regression, causing diskdump to fail on systems with certain adapters using the qla2xxx driver. * a race condition caused TX to stop in a guest using the virtio_net driver. * on some systems, using the "arp_validate=3" bonding option caused both links to show as "down" even though the arp_target was responding to ARP requests sent by the bonding driver. * in some circumstances, when a Red Hat Enterprise Linux client connected to a re-booted Windows-based NFS server, server-side filehandle-to-inode mapping changes caused a kernel panic. "bad_inode_ops" handling was changed to prevent this. Note: filehandle-to-inode mapping changes may still cause errors, but not panics. * when installing a Red Hat Enterprise Linux 4 guest via PXE, hard-coded fixed-size scatterlists could conflict with host requests, causing the guest"s kernel to panic. With this update, dynamically allocated scatterlists are used, resolving this issue. Enhancements: * kernel support for connlimit. Note: iptables errata update RHBA-2010:0395 is also required for connlimit to work correctly. * support for the Intel architectural performance monitoring subsystem . On supported CPUs, arch_perfmon offers means to mark performance events and options for configuring and counting these events. * kernel support for OProfile sampling of Intel microarchitecture CPUs. This update alone does not address OProfile support for such CPUs. A future oprofile package update will allow OProfile to work on Intel Nehalem CPUs. Users should upgrade to these updated packages, which contain backported patches to correct these issues and add these enhancements. The system must be rebooted for this update to take effect.