10 - RHSA-2012:0010

Problem Description:

Updated kernel-rt packages that fix several security issues and two bugs are now available for Red Hat Enterprise MRG 2.0.

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.

2. Relevant releases/architectures:

MRG Realtime for RHEL 6 Server v.2 - noarch, x86_64

3. Description:

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

This update fixes the following security issues:

* A malicious CIFS (Common Internet File System) server could send a specially-crafted response to a directory read request that would result in a denial of service or privilege escalation on a system that has a CIFS share mounted. (CVE-2011-3191, Important)

* The way fragmented IPv6 UDP datagrams over the bridge with UDP Fragmentation Offload (UFO) functionality on were handled could allow a remote attacker to cause a denial of service. (CVE-2011-4326, Important)

* GRO (Generic Receive Offload) fields could be left in an inconsistent state. An attacker on the local network could use this flaw to cause a denial of service. GRO is enabled by default in all network drivers that support it. (CVE-2011-2723, Moderate)

* IPv4 and IPv6 protocol sequence number and fragment ID generation could allow a man-in-the-middle attacker to inject packets and possibly hijack connections. Protocol sequence numbers and fragment IDs are now more random. (CVE-2011-3188, Moderate)

* A flaw in the FUSE (Filesystem in Userspace) implementation could allow a local user in the fuse group who has access to mount a FUSE file system to cause a denial of service. (CVE-2011-3353, Moderate)

* A flaw in the b43 driver. If a system had an active wireless interface that uses the b43 driver, an attacker able to send a specially-crafted frame to that interface could cause a denial of service. (CVE-2011-3359, Moderate)

* A flaw in the way CIFS shares with DFS referrals at their root were handled could allow an attacker on the local network, who is able to deploy a malicious CIFS server, to create a CIFS network share that, when mounted, would cause the client system to crash. (CVE-2011-3363, Moderate)

* A flaw in the m_stop() implementation could allow a local, unprivileged user to trigger a denial of service. (CVE-2011-3637, Moderate)

* Flaws in ghash_update() and ghash_final() could allow a local, unprivileged user to cause a denial of service. (CVE-2011-4081, Moderate)

* A flaw in the key management facility could allow a local, unprivileged user to cause a denial of service via the keyctl utility. (CVE-2011-4110, Moderate)

* A flaw in the Journaling Block Device (JBD) could allow a local attacker to crash the system by mounting a specially-crafted ext3 or ext4 disk. (CVE-2011-4132, Moderate)

* A flaw in the way memory containing security-related data was handled in tpm_read() could allow a local, unprivileged user to read the results of a previously run TPM command. (CVE-2011-1162, Low)

* I/O statistics from the taskstats subsystem could be read without any restrictions, which could allow a local, unprivileged user to gather confidential information, such as the length of a password used in a process. (CVE-2011-2494, Low)

* Flaws in tpacket_rcv() and packet_recvmsg() could allow a local, unprivileged user to leak information to user-space. (CVE-2011-2898, Low)

Red Hat would like to thank Darren Lavender for reporting CVE-2011-3191; Brent Meshier for reporting CVE-2011-2723; Dan Kaminsky for reporting CVE-2011-3188; Yogesh Sharma for reporting CVE-2011-3363; Nick Bowler for reporting CVE-2011-4081; Peter Huewe for reporting CVE-2011-1162; and Vasiliy Kulikov of Openwall for reporting CVE-2011-2494.

This update also fixes the following bugs:

* Previously, a mismatch in the build-id of the kernel-rt and the one in the related debuginfo package caused failures in SystemTap and perf. (BZ#768413)

* IBM x3650m3 systems were not able to boot the MRG Realtime kernel because they require a pmcraid driver that was not available. The pmcraid driver is included in this update. (BZ#753992)

Users should upgrade to these updated packages, which correct these issues. The system must be rebooted for this update to take effect.

4. 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/kb/docs/DOC-11259

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.

5. Bugs fixed (http://bugzilla.redhat.com/):

716842 - CVE-2011-2494 kernel: taskstats io infoleak 726552 - CVE-2011-2723 kernel: gro: only reset frag0 when skb can be pulled 728023 - CVE-2011-2898 kernel: af_packet: infoleak 732629 - CVE-2011-1162 kernel: tpm: infoleak 732658 - CVE-2011-3188 kernel: net: improve sequence number generation 732869 - CVE-2011-3191 kernel: cifs: signedness issue in CIFSFindNext() 736761 - CVE-2011-3353 kernel: fuse: check size of FUSE_NOTIFY_INVAL_ENTRY message 738202 - CVE-2011-3359 kernel: b43: allocate receive buffers big enough for max frame len + offset 738291 - CVE-2011-3363 kernel: cifs: always do is_path_accessible check in cifs_mount 747848 - CVE-2011-3637 kernel: proc: fix oops on invalid /proc//maps access 749475 - CVE-2011-4081 kernel: crypto: ghash: null pointer deref if no key is set 751297 - CVE-2011-4110 kernel: keys: NULL pointer deref in the user-defined key type 753341 - CVE-2011-4132 kernel: jbd/jbd2: invalid value of first log block leads to oops 755584 - CVE-2011-4326 kernel: wrong headroom check in udp6_ufo_fragment()