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.