kernel security update

ID CESA-2012:1323
Type centos
Reporter CentOS Project
Modified 2012-10-03T07:39:10


CentOS Errata and Security Advisory CESA-2012:1323

The kernel 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 socket buffers (skb) requiring TSO (TCP segment offloading) were handled by the sfc driver. If the skb did not fit within the minimum-size of the transmission queue, the network card could repeatedly reset itself. A remote attacker could use this flaw to cause a denial of service. (CVE-2012-3412, Important)

  • A use-after-free flaw was found in the xacct_add_tsk() function in the Linux kernel's taskstats subsystem. A local, unprivileged user could use this flaw to cause an information leak or a denial of service. (CVE-2012-3510, Moderate)

  • A buffer overflow flaw was found in the hfs_bnode_read() function in the HFS Plus (HFS+) file system implementation in the Linux kernel. A local user able to mount a specially-crafted HFS+ file system image could use this flaw to cause a denial of service or escalate their privileges. (CVE-2012-2319, 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 Ben Hutchings of Solarflare (tm) for reporting CVE-2012-3412, and Alexander Peslyak for reporting CVE-2012-3510. The CVE-2012-3430 issue was discovered by the Red Hat InfiniBand team.

This update also fixes the following bugs:

  • The cpuid_whitelist() function, masking the Enhanced Intel SpeedStep (EST) flag from all guests, prevented the "cpuspeed" service from working in the privileged Xen domain (dom0). CPU scaling was therefore not possible. With this update, cpuid_whitelist() is aware whether the domain executing CPUID is privileged or not, and enables the EST flag for dom0. (BZ#846125)

  • If a delayed-allocation write was performed before quota was enabled, the kernel displayed the following warning message:

    WARNING: at fs/quota/dquot.c:988 dquot_claim_space+0x77/0x112()

This was because information about the delayed allocation was not recorded in the quota structure. With this update, writes prior to enabling quota are properly accounted for, and the message is not displayed. (BZ#847326)

  • In Red Hat Enterprise Linux 5.9, the DSCP (Differentiated Services Code Point) netfilter module now supports mangling of the DSCP field. (BZ#847327)

  • Some subsystems clear the TIF_SIGPENDING flag during error handling in fork() paths. Previously, if the flag was cleared, the ERESTARTNOINTR error code could be returned. The underlying source code has been modified so that the error code is no longer returned. (BZ#847359)

  • An unnecessary check for the RXCW.CW bit could cause the Intel e1000e NIC (Network Interface Controller) to not work properly. The check has been removed so that the Intel e1000e NIC works as expected. (BZ#852448)

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

Merged security bulletin from advisories:

Affected packages: kernel kernel-PAE kernel-PAE-devel kernel-debug kernel-debug-devel kernel-devel kernel-doc kernel-headers kernel-xen kernel-xen-devel

Upstream details at: