RHSA-2011:1350 - Security Advisory

Topic

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.

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.

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.

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.1 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.1 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 6.1 s390x
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.1 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.1 i386
• Red Hat Virtual Storage Appliance (from RHUI) 6.1 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.1 ppc64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

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

CVEs

• CVE-2011-1746
• CVE-2011-1745
• CVE-2011-2022
• CVE-2011-1160
• CVE-2011-2496
• CVE-2011-2484
• CVE-2011-2723
• CVE-2011-2898
• CVE-2011-1833
• CVE-2011-2521
• CVE-2011-2918

References

• https://access.redhat.com/security/updates/classification/#important
• https://rhn.redhat.com/errata/RHSA-2011-1241.html
• https://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/6.1_Technical_Notes/kernel.html#RHSA-2011-1350