1.74.5. RHSA-2011:0927: 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:

* An integer overflow flaw in ib_uverbs_poll_cq() could allow a local, unprivileged user to cause a denial of service or escalate their privileges. (CVE-2010-4649, Important)

* A race condition in the way new InfiniBand connections were set up could allow a remote user to cause a denial of service. (CVE-2011-0695, Important)

* A flaw in the Stream Control Transmission Protocol (SCTP) implementation could allow a remote attacker to cause a denial of service if the sysctl "net.sctp.addip_enable" variable was turned on (it is off by default). (CVE-2011-1573, Important)

* Flaws in the AGPGART driver implementation when handling certain IOCTL commands could allow a local, unprivileged user to cause a denial of service or escalate their privileges. (CVE-2011-1745, CVE-2011-2022, Important)

* An integer overflow flaw in agp_allocate_memory() could allow a local, unprivileged user to cause a denial of service or escalate their privileges. (CVE-2011-1746, Important)

* A flaw allowed napi_reuse_skb() to be called on VLAN (virtual LAN) packets. An attacker on the local network could trigger this flaw by sending specially-crafted packets to a target system, possibly causing a denial of service. (CVE-2011-1576, Moderate)

* An integer signedness error in next_pidmap() could allow a local, unprivileged user to cause a denial of service. (CVE-2011-1593, Moderate)

* A flaw in the way the Xen hypervisor implementation handled CPUID instruction emulation during virtual machine exits could allow an unprivileged guest user to crash a guest. This only affects systems that have an Intel x86 processor with the Intel VT-x extension enabled. (CVE-2011-1936, Moderate)

* A flaw in inet_diag_bc_audit() could allow a local, unprivileged user to cause a denial of service (infinite loop). (CVE-2011-2213, Moderate)

* A missing initialization flaw in the XFS file system implementation could lead to an information leak. (CVE-2011-0711, Low)

* A flaw in ib_uverbs_poll_cq() could allow a local, unprivileged user to cause an information leak. (CVE-2011-1044, Low)

* A missing validation check was found in the signals implementation. A local, unprivileged user could use this flaw to send signals via the sigqueueinfo system call, with the si_code set to SI_TKILL and with spoofed process and user IDs, to other processes. Note: This flaw does not allow existing permission checks to be bypassed; signals can only be sent if your privileges allow you to already do so. (CVE-2011-1182, Low)

* A heap overflow flaw in the EFI GUID Partition Table (GPT) implementation could allow a local attacker to cause a denial of service by mounting a disk containing specially-crafted partition tables. (CVE-2011-1776, Low)

* Structure padding in two structures in the Bluetooth implementation was not initialized properly before being copied to user-space, possibly allowing local, unprivileged users to leak kernel stack memory to user-space. (CVE-2011-2492, Low)

Red Hat would like to thank Jens Kuehnel for reporting CVE-2011-0695; Vasiliy Kulikov for reporting CVE-2011-1745, CVE-2011-2022, and CVE-2011-1746; Ryan Sweat for reporting CVE-2011-1576; Robert Swiecki for reporting CVE-2011-1593; Dan Rosenberg for reporting CVE-2011-2213 and CVE-2011-0711; Julien Tinnes of the Google Security Team for reporting CVE-2011-1182; Timo Warns for reporting CVE-2011-1776; and Marek Kroemeke and Filip Palian for reporting CVE-2011-2492.

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.