kernel security update

CentOS Errata and Security Advisory CESA-2010:0046

The kernel packages contain the Linux kernel, the core of any Linux
operating system.

Security fixes:

• an array index error was found in the gdth driver. A local user could
  send a specially-crafted IOCTL request that would cause a denial of service
  or, possibly, privilege escalation. (CVE-2009-3080, Important)

• a flaw was found in the FUSE implementation. When a system is low on
  memory, fuse_put_request() could dereference an invalid pointer, possibly
  leading to a local denial of service or privilege escalation.
  (CVE-2009-4021, Important)

• Tavis Ormandy discovered a deficiency in the fasync_helper()
  implementation. This could allow a local, unprivileged user to leverage a
  use-after-free of locked, asynchronous file descriptors to cause a denial
  of service or privilege escalation. (CVE-2009-4141, Important)

• the Parallels Virtuozzo Containers team reported the RHSA-2009:1243
  update introduced two flaws in the routing implementation. If an attacker
  was able to cause a large enough number of collisions in the routing hash
  table (via specially-crafted packets) for the emergency route flush to
  trigger, a deadlock could occur. Secondly, if the kernel routing cache was
  disabled, an uninitialized pointer would be left behind after a route
  lookup, leading to a kernel panic. (CVE-2009-4272, Important)

• the RHSA-2009:0225 update introduced a rewrite attack flaw in the
  do_coredump() function. A local attacker able to guess the file name a
  process is going to dump its core to, prior to the process crashing, could
  use this flaw to append data to the dumped core file. This issue only
  affects systems that have “/proc/sys/fs/suid_dumpable” set to 2 (the
  default value is 0). (CVE-2006-6304, Moderate)

The fix for CVE-2006-6304 changes the expected behavior: With suid_dumpable
set to 2, the core file will not be recorded if the file already exists.
For example, core files will not be overwritten on subsequent crashes of
processes whose core files map to the same name.

• an information leak was found in the Linux kernel. On AMD64 systems,
  32-bit processes could access and read certain 64-bit registers by
  temporarily switching themselves to 64-bit mode. (CVE-2009-2910, Moderate)

• the RHBA-2008:0314 update introduced N_Port ID Virtualization (NPIV)
  support in the qla2xxx driver, resulting in two new sysfs pseudo files,
  “/sys/class/scsi_host/[a qla2xxx host]/vport_create” and “vport_delete”.
  These two files were world-writable by default, allowing a local user to
  change SCSI host attributes. This flaw only affects systems using the
  qla2xxx driver and NPIV capable hardware. (CVE-2009-3556, Moderate)

• permission issues were found in the megaraid_sas driver. The “dbg_lvl”
  and “poll_mode_io” files on the sysfs file system (“/sys/”) had
  world-writable permissions. This could allow local, unprivileged users to
  change the behavior of the driver. (CVE-2009-3889, CVE-2009-3939, Moderate)

• a NULL pointer dereference flaw was found in the firewire-ohci driver
  used for OHCI compliant IEEE 1394 controllers. A local, unprivileged user
  with access to /dev/fw* files could issue certain IOCTL calls, causing a
  denial of service or privilege escalation. The FireWire modules are
  blacklisted by default, and if enabled, only root has access to the files
  noted above by default. (CVE-2009-4138, Moderate)

• a buffer overflow flaw was found in the hfs_bnode_read() function in the
  HFS file system implementation. This could lead to a denial of service if a
  user browsed a specially-crafted HFS file system, for example, by running
  “ls”. (CVE-2009-4020, Low)

Bug fix documentation for this update will be available shortly from
www.redhat.com/docs/en-US/errata/RHSA-2010-0046/Kernel_Security_Update/
index.html

Users should 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:
https://lists.centos.org/pipermail/centos-announce/2010-January/078641.html
https://lists.centos.org/pipermail/centos-announce/2010-January/078642.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://access.redhat.com/errata/RHSA-2010:0046