1.74.6. RHSA-2011:0833: Important kernel security and bug fix update

Updated kernel packages that fix multiple security issues and several bugs are now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having important security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.

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

This update fixes the following security issues:

* A flaw in the dccp_rcv_state_process() function could allow a remote attacker to cause a denial of service, even when the socket was already closed. (CVE-2011-1093, Important)

* Multiple buffer overflow flaws were found in the Linux kernel's Management Module Support for Message Passing Technology (MPT) based controllers. A local, unprivileged user could use these flaws to cause a denial of service, an information leak, or escalate their privileges. (CVE-2011-1494, CVE-2011-1495, Important)

* A missing validation of a null-terminated string data structure element in the bnep_sock_ioctl() function could allow a local user to cause an information leak or a denial of service. (CVE-2011-1079, Moderate)

* Missing error checking in the way page tables were handled in the Xen hypervisor implementation could allow a privileged guest user to cause the host, and the guests, to lock up. (CVE-2011-1166, Moderate)

* A flaw was found in the way the Xen hypervisor implementation checked for the upper boundary when getting a new event channel port. A privileged guest user could use this flaw to cause a denial of service or escalate their privileges. (CVE-2011-1763, Moderate)

* The start_code and end_code values in "/proc/[pid]/stat" were not protected. In certain scenarios, this flaw could be used to defeat Address Space Layout Randomization (ASLR). (CVE-2011-0726, Low)

* A missing initialization flaw in the sco_sock_getsockopt() function could allow a local, unprivileged user to cause an information leak. (CVE-2011-1078, Low)

* A missing validation of a null-terminated string data structure element in the do_replace() function could allow a local user who has the CAP_NET_ADMIN capability to cause an information leak. (CVE-2011-1080, Low)

* A buffer overflow flaw in the DEC Alpha OSF partition implementation in the Linux kernel could allow a local attacker to cause an information leak by mounting a disk that contains specially-crafted partition tables. (CVE-2011-1163, Low)

* Missing validations of null-terminated string data structure elements in the do_replace(), compat_do_replace(), do_ipt_get_ctl(), do_ip6t_get_ctl(), and do_arpt_get_ctl() functions could allow a local user who has the CAP_NET_ADMIN capability to cause an information leak. (CVE-2011-1170, CVE-2011-1171, CVE-2011-1172, Low)

* A heap overflow flaw in the Linux kernel's EFI GUID Partition Table (GPT) implementation could allow a local attacker to cause a denial of service by mounting a disk that contains specially-crafted partition tables. (CVE-2011-1577, Low)

Red Hat would like to thank Dan Rosenberg for reporting CVE-2011-1494 and CVE-2011-1495; Vasiliy Kulikov for reporting CVE-2011-1079, CVE-2011-1078, CVE-2011-1080, CVE-2011-1170, CVE-2011-1171, and CVE-2011-1172; Kees Cook for reporting CVE-2011-0726; and Timo Warns for reporting CVE-2011-1163 and CVE-2011-1577.

This update also fixes several bugs and adds various enhancements. Documentation for these bug fixes and enhancements is available in the Red Hat Enterprise Linux 5.6 Technical Notes.

Users should upgrade to these updated packages, which contain backported patches to correct these issues, and fix the bugs noted in the Technical Notes. The system must be rebooted for this update to take effect.