Red Hat: Kernel Important Fix Denial of Service RHSA-2009:0459-01

The kernel packages contain the Linux kernel, the core of any Linux operating system.
Security fixes:
* a logic error was found in the do_setlk() function of the Linux kernel Network File System (NFS) implementation. If a signal interrupted a lock request, the local POSIX lock was incorrectly created. This could cause a denial of service on the NFS server if a file descriptor was closed before its corresponding lock request returned. (CVE-2008-4307, Important)
* a deficiency was found in the Linux kernel system call auditing implementation on 64-bit systems. This could allow a local, unprivileged user to circumvent a system call audit configuration, if that configuration filtered based on the "syscall" number or arguments. (CVE-2009-0834, Important)
* Chris Evans reported a deficiency in the Linux kernel signals implementation. The clone() system call permits the caller to indicate the signal it wants to receive when its child exits. When clone() is called with the CLONE_PARENT flag, it permits the caller to clone a new child that shares the same parent as itself, enabling the indicated signal to be sent to the caller's parent (instead of the caller), even if the caller's parent has different real and effective user IDs. This could lead to a denial of service of the parent. (CVE-2009-0028, Moderate)
* the sock_getsockopt() function in the Linux kernel did not properly initialize a data structure that can be directly returned to user-space when the getsockopt() function is called with SO_BSDCOMPAT optname set. This flaw could possibly lead to memory disclosure. (CVE-2009-0676, Moderate)
Bug fixes:
* a kernel crash may have occurred for Red Hat Enterprise Linux 4.7 guests if their guest configuration file specified "vif = [ "type=ioemu" ]". This crash only occurred when starting guests via the "xm create" command. (BZ#477146)
* a bug in IO-APIC NMI watchdog may have prevented Red Hat Enterprise Linux 4.7 from being installed on HP ProLiant DL580 G5 systems. Hangs during installation and "NMI received for unknown reason [xx]" errors may have occurred. (BZ#479184)
* a kernel deadlock on some systems when using netdump through a network interface that uses the igb driver. (BZ#480579)
* a possible kernel hang in sys_ptrace() on the Itanium® architecture, possibly triggered by tracing a threaded process with strace. (BZ#484904)
* the RHSA-2008:0665 errata only fixed the known problem with the LSI Logic LSI53C1030 Ultra320 SCSI controller, for tape devices. Read commands sent to tape devices may have received incorrect data. This issue may have led to data corruption. This update includes a fix for all types of devices. (BZ#487399)
* a missing memory barrier caused a race condition in the AIO subsystem between the read_events() and aio_complete() functions. This may have caused a thread in read_events() to sleep indefinitely, possibly causing an application hang. (BZ#489935)
* due to a lack of synchronization in the NFS client code, modifications to some pages (for files on an NFS mounted file system) made through a region of memory mapped by mmap() may be lost if the NFS client invalidates its page cache for particular files. (BZ#490119)
* a NULL pointer dereference in the megaraid_mbox driver caused a system crash on some systems. (BZ#493420)
* the ext3_symlink() function in the ext3 file system code used an illegal __GFP_FS allocation inside some transactions. This may have resulted in a kernel panic and "Assertion failure" errors. (BZ#493422)
* do_machine_check() cleared all Machine Check Exception (MCE) status registers, preventing the BIOS from using them to determine the cause of certain panics and errors. (BZ#494915)
* a bug prevented NMI watchdog from initializing on HP ProLiant DL580 G5 systems. (BZ#497330)
This update contains backported patches to fix these issues. The system must be rebooted for this update to take effect.