RHSA-2010:0161 - Security Advisory

Topic

Updated kernel-rt packages that fix multiple security issues and several
bugs are now available for Red Hat Enterprise MRG 1.2.

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

This update fixes the following security issues:

• a deficiency was found in the fasync_helper() implementation. This could

allow a local, unprivileged user to leverage a use-after-free of locked,
asynchronous file descriptors to cause a denial of service or privilege
escalation. (CVE-2009-4141, Important)

• multiple flaws were found in the mmap and mremap implementations. A

local, unprivileged user could use these flaws to cause a local denial of
service or escalate their privileges. (CVE-2010-0291, Important)

• a missing boundary check was found in the do_move_pages() function in the

memory migration functionality. A local user could use this flaw to cause a
local denial of service or an information leak. (CVE-2010-0415, Important)

• a NULL pointer dereference flaw was found in the ip6_dst_lookup_tail()

function. An attacker on the local network could trigger this flaw by
sending IPv6 traffic to a target system, leading to a system crash (kernel
OOPS) if dst->neighbour is NULL on the target system when receiving an IPv6
packet. (CVE-2010-0437, Important)

• a NULL pointer dereference flaw was found in the Fast Userspace Mutexes

(futexes) implementation. The unlock code path did not check if the futex
value associated with pi_state->owner had been modified. A local user could
use this flaw to modify the futex value, possibly leading to a denial of
service or privilege escalation when the pi_state->owner pointer is
dereferenced. (CVE-2010-0622, Important)

• an information leak was found in the print_fatal_signal() implementation.

When "/proc/sys/kernel/print-fatal-signals" is set to 1 (the default value
is 0), memory that is reachable by the kernel could be leaked to
user-space. This issue could also result in a system crash. Note that this
flaw only affected the i386 architecture. (CVE-2010-0003, Moderate)

• a flaw was found in the kernel connector implementation. A local,

unprivileged user could trigger this flaw by sending an arbitrary amount of
notification requests using specially-crafted netlink messages, resulting
in a denial of service. (CVE-2010-0410, Moderate)

• missing capability checks were found in the ebtables implementation, used

for creating an Ethernet bridge firewall. This could allow a local,
unprivileged user to bypass intended capability restrictions and modify
ebtables rules. (CVE-2010-0007, Low)

This update also fixes the following bugs:

• references were missing for two LSI MegaRAID SAS controllers already

supported by the kernel, preventing systems using these controllers from
booting. (BZ#554664)

• a typo in the fix for CVE-2009-2691 resulted in gdb being unable to read

core files created by gcore. (BZ#554965)

• values for certain pointers used by the kernel, which should be

undereferencable, could potentially be abused when a kernel OOPS occurs.
Values that are harder to dereference are now used. (BZ#555227)

• this update redesigns the locking scheme of the TTY process group

(tty->pgrp) structure, due to race conditions introduced when tty->pgrp
started using struct pid instead of pid_t. (BZ#559101)

• the way the NFS kernel server used iget() and the way in which it kept

its cache of inode information, could have led to (mainly on busy file
servers) inconsistencies between the local file system and the file system
being served to clients. (BZ#561275)

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.

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
http://kbase.redhat.com/faq/docs/DOC-11259

Affected Products

• MRG Realtime 1 x86_64
• MRG Realtime 1 i386

Fixes

• BZ - 547906 - CVE-2009-4141 kernel: create_elf_tables can leave urandom in a bad state
• BZ - 554578 - CVE-2010-0003 kernel: infoleak if print-fatal-signals=1
• BZ - 554664 - MRG current has a very old megaraid_sas driver
• BZ - 554965 - gcore tool produces unusable corefile with MRG kernel
• BZ - 555238 - CVE-2010-0007 kernel: netfilter: ebtables: enforce CAP_NET_ADMIN
• BZ - 556703 - CVE-2010-0291 kernel: untangle the do_mremap()
• BZ - 561275 - kernel: serious ugliness in iget() uses by nfsd [mrg-1]
• BZ - 561682 - CVE-2010-0410 kernel: OOM/crash in drivers/connector
• BZ - 562582 - CVE-2010-0415 kernel: sys_move_pages infoleak
• BZ - 563091 - CVE-2010-0622 kernel: futex: Handle user space corruption gracefully
• BZ - 563781 - CVE-2010-0437 kernel: ipv6: fix ip6_dst_lookup_tail() NULL pointer dereference

CVEs

• CVE-2009-4895
• CVE-2009-4141
• CVE-2010-0291
• CVE-2010-0622
• CVE-2010-0410
• CVE-2010-0437
• CVE-2010-0003
• CVE-2010-0007
• CVE-2010-0415

References

• http://www.redhat.com/security/updates/classification/#important