Issued:
2012-12-04
Updated:
2012-12-04

RHSA-2012:1491 - Important: kernel-rt security and bug fix update

Synopsis

Important: kernel-rt security and bug fix update

Type/Severity

Security Advisory Important

Topic

Updated kernel-rt packages that fix several security issues and multiple bugs are now available for Red Hat Enterprise MRG 2.2.

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.

Description

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

This update fixes the following security issues:

  • A flaw was found in the way Netlink messages without SCM_CREDENTIALS (used for authentication) data set were handled. When not explicitly set, the data was sent but with all values set to 0, including the process ID and user ID, causing the Netlink message to appear as if it were sent with root privileges. A local, unprivileged user could use this flaw to send spoofed Netlink messages to an application, possibly resulting in the application performing privileged operations if it relied on SCM_CREDENTIALS data for the authentication of Netlink messages. (CVE-2012-3520, Important)

  • A race condition was found in the way asynchronous I/O and fallocate() interacted when using the ext4 file system. A local, unprivileged user could use this flaw to expose random data from an extent whose data blocks have not yet been written, and thus contain data from a deleted file. (CVE-2012-4508, Important)

  • A use-after-free flaw was found in the Linux kernel's memory management subsystem in the way quota handling for huge pages was performed. A local, unprivileged user could use this flaw to cause a denial of service or, potentially, escalate their privileges. (CVE-2012-2133, Moderate)

  • A use-after-free flaw was found in the madvise() system call implementation in the Linux kernel. A local, unprivileged user could use this flaw to cause a denial of service or, potentially, escalate their privileges. (CVE-2012-3511, Moderate)

  • A divide-by-zero flaw was found in the TCP Illinois congestion control algorithm implementation in the Linux kernel. If the TCP Illinois congestion control algorithm were in use (the sysctl net.ipv4.tcp_congestion_control variable set to "illinois"), a local, unprivileged user could trigger this flaw and cause a denial of service. (CVE-2012-4565, Moderate)

  • An information leak flaw was found in the uname() system call implementation in the Linux kernel. A local, unprivileged user could use this flaw to leak kernel stack memory to user-space by setting the UNAME26 personality and then calling the uname() system call. (CVE-2012-0957, Low)

  • Buffer overflow flaws were found in the udf_load_logicalvol() function in the Universal Disk Format (UDF) file system implementation in the Linux kernel. An attacker with physical access to a system could use these flaws to cause a denial of service or escalate their privileges. (CVE-2012-3400, Low)

  • A flaw was found in the way the msg_namelen variable in the rds_recvmsg() function of the Linux kernel's Reliable Datagram Sockets (RDS) protocol implementation was initialized. A local, unprivileged user could use this flaw to leak kernel stack memory to user-space. (CVE-2012-3430, Low)

Red Hat would like to thank Pablo Neira Ayuso for reporting CVE-2012-3520; Theodore Ts'o for reporting CVE-2012-4508; Shachar Raindel for reporting CVE-2012-2133; and Kees Cook for reporting CVE-2012-0957. Upstream acknowledges Dmitry Monakhov as the original reporter of CVE-2012-4508. The CVE-2012-4565 issue was discovered by Rodrigo Freire of Red Hat, and the CVE-2012-3430 issue was discovered by the Red Hat InfiniBand team.

This update also fixes multiple bugs. Documentation for these changes will be available shortly from the Technical Notes document linked to in the References section.

Users should upgrade to these updated packages, which upgrade the kernel-rt kernel to version kernel-rt-3.2.33-rt50, and correct these issues. The system must be rebooted for this update to take effect.

Solution

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 https://access.redhat.com/knowledge/articles/11258

To install kernel packages manually, use "rpm -ivh [package]". Do not use "rpm -Uvh" as that will remove the running kernel binaries from your system. You may use "rpm -e" to remove old kernels after determining that the new kernel functions properly on your system.

Affected Products

ProductVersionArch
MRG Realtime2x86_64

Updated Packages

  • kernel-rt-3.2.33-rt50.66.el6rt.x86_64.rpm
  • kernel-rt-debuginfo-3.2.33-rt50.66.el6rt.x86_64.rpm
  • mrg-rt-release-3.2.33-rt50.66.el6rt.noarch.rpm
  • kernel-rt-firmware-3.2.33-rt50.66.el6rt.noarch.rpm
  • kernel-rt-vanilla-devel-3.2.33-rt50.66.el6rt.x86_64.rpm
  • kernel-rt-debug-3.2.33-rt50.66.el6rt.x86_64.rpm
  • kernel-rt-trace-3.2.33-rt50.66.el6rt.x86_64.rpm
  • kernel-rt-vanilla-3.2.33-rt50.66.el6rt.x86_64.rpm
  • kernel-rt-debug-debuginfo-3.2.33-rt50.66.el6rt.x86_64.rpm
  • kernel-rt-doc-3.2.33-rt50.66.el6rt.noarch.rpm
  • kernel-rt-trace-debuginfo-3.2.33-rt50.66.el6rt.x86_64.rpm
  • kernel-rt-debuginfo-common-x86_64-3.2.33-rt50.66.el6rt.x86_64.rpm
  • kernel-rt-devel-3.2.33-rt50.66.el6rt.x86_64.rpm
  • kernel-rt-3.2.33-rt50.66.el6rt.src.rpm
  • kernel-rt-trace-devel-3.2.33-rt50.66.el6rt.x86_64.rpm
  • kernel-rt-vanilla-debuginfo-3.2.33-rt50.66.el6rt.x86_64.rpm
  • kernel-rt-debug-devel-3.2.33-rt50.66.el6rt.x86_64.rpm

Fixes

CVEs

References

Additional information