RHSA-2008:0233 - Security Advisory

Topic

Updated kernel packages that fix various security issues and several bugs
are now available for Red Hat Enterprise Linux 5.

This update has been rated as having important security impact by the Red
Hat Security Response Team.

Description

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

These updated packages fix the following security issues:

• the absence of a protection mechanism when attempting to access a

critical section of code has been found in the Linux kernel open file
descriptors control mechanism, fcntl. This could allow a local unprivileged
user to simultaneously execute code, which would otherwise be protected
against parallel execution. As well, a race condition when handling locks
in the Linux kernel fcntl functionality, may have allowed a process
belonging to a local unprivileged user to gain re-ordered access to the
descriptor table. (CVE-2008-1669, Important)

• a possible hypervisor panic was found in the Linux kernel. A privileged

user of a fully virtualized guest could initiate a stress-test File
Transfer Protocol (FTP) transfer between the guest and the hypervisor,
possibly leading to hypervisor panic. (CVE-2008-1619, Important)

• the absence of a protection mechanism when attempting to access a

critical section of code, as well as a race condition, have been found
in the Linux kernel file system event notifier, dnotify. This could allow a
local unprivileged user to get inconsistent data, or to send arbitrary
signals to arbitrary system processes. (CVE-2008-1375, Important)

Red Hat would like to thank Nick Piggin for responsibly disclosing the
following issue:

• when accessing kernel memory locations, certain Linux kernel drivers

registering a fault handler did not perform required range checks. A local
unprivileged user could use this flaw to gain read or write access to
arbitrary kernel memory, or possibly cause a kernel crash.
(CVE-2008-0007, Important)

• the absence of sanity-checks was found in the hypervisor block backend

driver, when running 32-bit paravirtualized guests on a 64-bit host. The
number of blocks to be processed per one request from guest to host, or
vice-versa, was not checked for its maximum value, which could have allowed
a local privileged user of the guest operating system to cause a denial of
service. (CVE-2007-5498, Important)

• it was discovered that the Linux kernel handled string operations in the

opposite way to the GNU Compiler Collection (GCC). This could allow a local
unprivileged user to cause memory corruption. (CVE-2008-1367, Low)

As well, these updated packages fix the following bugs:

• on IBM System z architectures, when running QIOASSIST enabled QDIO

devices in an IBM z/VM environment, the output queue stalled under heavy
load. This caused network performance to degrade, possibly causing network
hangs and outages.

• multiple buffer overflows were discovered in the neofb video driver. It

was not possible for an unprivileged user to exploit these issues, and as
such, they have not been handled as security issues.

• when running Microsoft Windows in a HVM, a bug in vmalloc/vfree caused

network performance to degrade.

• on certain architectures, a bug in the libATA sata_nv driver may have

caused infinite reboots, and an "ata1: CPB flags CMD err flags 0x11" error.

• repeatedly hot-plugging a PCI Express card may have caused "Bad DLLP"

errors.

• a NULL pointer dereference in NFS, which may have caused applications to

crash, has been resolved.

• when attempting to kexec reboot, either manually or via a panic-triggered

kdump, the Unisys ES7000/one hanged after rebooting in the new kernel,
after printing the "Memory: 32839688k/33685504k available" line.

Red Hat Enterprise Linux 5 users are advised to upgrade to these updated
packages, which contain backported patches to resolve these issues.

Solution

Before applying this update, make sure that all previously-released
errata relevant to your system have been applied.

This update is available via Red Hat Network. Details on how to use
the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/FAQ_58_10188

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.1 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.1 ia64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.1 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 5.1 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 5.1 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 369531 - CVE-2007-5498 missing sanity check in xen block backend driver
• BZ - 412071 - LTC37008-QDIO based network connections hang with QIOASSIST ON
• BZ - 427400 - CVE-2008-1619 [xen-ia64] Dom0 panic while we run ftp test tool between HVM and Dom0.
• BZ - 428961 - CVE-2008-0007 kernel: insufficient range checks in fault handlers with mremap
• BZ - 433616 - [Xen] vmalloc/vfree on HVM Guest/IA64 does untolerate performance.
• BZ - 433617 - libata: sata_nv may send commands with duplicate tags [5.1.z]
• BZ - 437312 - CVE-2008-1367 Kernel doesn't clear DF for signal handlers
• BZ - 437770 - CVE-2008-1619 [xen-ia64] Dom0 panic while we run ftp test tool between HVM and Dom0.
• BZ - 439754 - CVE-2008-1375 kernel: race condition in dnotify (local DoS, local roothole possible)
• BZ - 440438 - [5.1] PCI Express hotplug driver problem (Bad DLLP) [rhel-5.1.z]
• BZ - 440447 - 2.6.18-53.1.12 crashes on NULL pointer dereference with NFS on the stack [rhel-5.1.z]
• BZ - 442922 - kexec or kdump hangs on ES7000/ONE
• BZ - 443433 - CVE-2008-1669 kernel: add rcu_read_lock() to fcheck() in both dnotify, locks.c and fix fcntl store/load race in locks.c

CVEs

• CVE-2008-1669
• CVE-2008-0007
• CVE-2008-1367
• CVE-2008-1375
• CVE-2007-5498
• CVE-2008-1619

References

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