6.9 - RHSA-2011:1350

Problem Description:

Updated kernel packages that fix several security issues, various bugs, and add one enhancement are now available for Red Hat Enterprise Linux 6.

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:

Red Hat Enterprise Linux Desktop (v. 6) - i386, noarch, x86_64 Red Hat Enterprise Linux HPC Node (v. 6) - noarch, x86_64 Red Hat Enterprise Linux Server (v. 6) - i386, noarch, ppc64, s390x, x86_64 Red Hat Enterprise Linux Workstation (v. 6) - i386, noarch, x86_64

3. Description:

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

This update fixes the following security issues:

* Flaws in the AGPGART driver implementation when handling certain IOCTL commands could allow a local 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 user to cause a denial of service or escalate their privileges. (CVE-2011-1746, Important)

* A race condition flaw was found in the Linux kernel's eCryptfs implementation. A local attacker could use the mount.ecryptfs_private utility to mount (and then access) a directory they would otherwise not have access to. Note: To correct this issue, the RHSA-2011:1241 ecryptfs-utils update, which provides the user-space part of the fix, must also be installed. (CVE-2011-1833, Moderate)

* A denial of service flaw was found in the way the taskstats subsystem handled the registration of process exit handlers. A local, unprivileged user could register an unlimited amount of these handlers, leading to excessive CPU time and memory use. (CVE-2011-2484, Moderate)

* A flaw was found in the way mapping expansions were handled. A local, unprivileged user could use this flaw to cause a wrapping condition, triggering a denial of service. (CVE-2011-2496, Moderate)

* A flaw was found in the Linux kernel's Performance Events implementation. It could falsely lead the NMI (Non-Maskable Interrupt) Watchdog to detect a lockup and panic the system. A local, unprivileged user could use this flaw to cause a denial of service (kernel panic) using the perf tool. (CVE-2011-2521, Moderate)

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

* A flaw was found in the way the Linux kernel's Performance Events implementation handled PERF_COUNT_SW_CPU_CLOCK counter overflow. A local, unprivileged user could use this flaw to cause a denial of service. (CVE-2011-2918, Moderate)

* A flaw was found in the Linux kernel's Trusted Platform Module (TPM) implementation. A local, unprivileged user could use this flaw to leak information to user-space. (CVE-2011-1160, Low)

* Flaws were found in the tpacket_rcv() and packet_recvmsg() functions in the Linux kernel. A local, unprivileged user could use these flaws to leak information to user-space. (CVE-2011-2898, Low)

Red Hat would like to thank Vasiliy Kulikov of Openwall for reporting CVE-2011-1745, CVE-2011-2022, CVE-2011-1746, and CVE-2011-2484; the Ubuntu Security Team for reporting CVE-2011-1833; Robert Swiecki for reporting CVE-2011-2496; Li Yu for reporting CVE-2011-2521; Brent Meshier for reporting CVE-2011-2723; and Peter Huewe for reporting CVE-2011-1160. The Ubuntu Security Team acknowledges Vasiliy Kulikov of Openwall and Dan Rosenberg as the original reporters of CVE-2011-1833.

This update also fixes various bugs and adds one enhancement. 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 contain backported patches to correct these issues, and fix the bugs and add the enhancement noted in the Technical Notes. 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/):

684671 - CVE-2011-1160 kernel: tpm infoleaks 698996 - CVE-2011-1745 CVE-2011-2022 kernel: agp: insufficient pg_start parameter checking in AGPIOC_BIND and AGPIOC_UNBIND ioctls 698998 - CVE-2011-1746 kernel: agp: insufficient page_count parameter checking in agp_allocate_memory() 713463 - UV: fscache taints kernel; NFS requires fscache; NFS taints kernel 715436 - CVE-2011-2484 kernel: taskstats: duplicate entries in listener mode can lead to DoS 716538 - CVE-2011-2496 kernel: mm: avoid wrapping vm_pgoff in mremap() and stack expansions 719228 - CVE-2011-2521 kernel: perf, x86: fix Intel fixed counters base initialization 726552 - CVE-2011-2723 kernel: gro: only reset frag0 when skb can be pulled 728023 - CVE-2011-2898 kernel: af_packet: infoleak 730706 - CVE-2011-2918 kernel: perf: Fix software event overflow 731172 - CVE-2011-1833 kernel: ecryptfs: mount source TOCTOU race 732379 - [bnx2x_extract_max_cfg:1079(ethxx)]Illegal configuration detected for Max BW - using 100 instead [rhel-6.1.z]