Important: kernel security and bug fix update

Updated kernel packages that fix multiple security issues and three bugs
are now available for Red Hat Enterprise Linux 4.

This update has been rated as having important security impact by the Red
Hat Security Response Team.

The kernel packages contain the Linux kernel, the core of any Linux
operating 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 a
denial of service or, possibly, privilege escalation. (CVE-2009-3080,
Important)

* a flaw was found in the collect_rx_frame() function in the HiSax ISDN
driver (hfc_usb) in the Linux kernel. An attacker could use this flaw to
send a specially-crafted HDLC packet that could trigger a buffer out of
bounds, possibly resulting in a denial of service. (CVE-2009-4005,
Important)

* permission issues were found in the megaraid_sas driver (for SAS based
RAID controllers) in the Linux kernel. 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 buffer overflow flaw was found in the hfs_bnode_read() function in the
HFS file system implementation in the Linux kernel. 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)

This update also fixes the following bugs:

* if a process was using ptrace() to trace a multi-threaded process, and
that multi-threaded process dumped its core, the process performing the
trace could hang in wait4(). This issue could be triggered by running
"strace -f" on a multi-threaded process that was dumping its core,
resulting in the strace command hanging. (BZ#555869)

* a bug in the ptrace() implementation could have, in some cases, caused
ptrace_detach() to create a zombie process if the process being traced
was terminated with a SIGKILL signal. (BZ#555869)

* the RHSA-2010:0020 update resolved an issue (CVE-2009-4537) in the
Realtek r8169 Ethernet driver. This update implements a better solution for
that issue. Note: This is not a security regression. The original fix was
complete. This update is adding the official upstream fix. (BZ#556406)

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.

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/docs/DOC-11259

526068 - CVE-2009-3889 CVE-2009-3939 kernel: megaraid_sas permissions in sysfs
539414 - CVE-2009-3080 kernel: gdth: Prevent negative offsets in ioctl
539435 - CVE-2009-4005 kernel: isdn: hfc_usb: fix read buffer overflow
540736 - CVE-2009-4020 kernel: hfs buffer overflow
555869 - [4.7] wait4 blocks on non-existing pid [rhel-4.8.z]
556406 - kernel: r8169: straighten out overlength frame detection (improved) [rhel-4.9] [rhel-4.8.z]

https://www.redhat.com/security/data/cve/CVE-2009-3080.html
https://www.redhat.com/security/data/cve/CVE-2009-3889.html
https://www.redhat.com/security/data/cve/CVE-2009-3939.html
https://www.redhat.com/security/data/cve/CVE-2009-4005.html
https://www.redhat.com/security/data/cve/CVE-2009-4020.html
http://www.redhat.com/security/updates/classification/#important