Synopsis

Important: kernel security and bug fix update

Type/Severity

Security Advisory: Important

Topic

Updated kernel packages that fix several 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.

Security fixes:

• several flaws were found in the way the Linux kernel CIFS implementation

handles Unicode strings. CIFS clients convert Unicode strings sent by a
server to their local character sets, and then write those strings into
memory. If a malicious server sent a long enough string, it could write
past the end of the target memory region and corrupt other memory areas,
possibly leading to a denial of service or privilege escalation on the
client mounting the CIFS share. (CVE-2009-1439, CVE-2009-1633, Important)

• the Linux kernel Network File System daemon (nfsd) implementation did not

drop the CAP_MKNOD capability when handling requests from local,
unprivileged users. This flaw could possibly lead to an information leak or
privilege escalation. (CVE-2009-1072, Moderate)

• Frank Filz reported the NFSv4 client was missing a file permission check

for the execute bit in some situations. This could allow local,
unprivileged users to run non-executable files on NFSv4 mounted file
systems. (CVE-2009-1630, Moderate)

• a missing check was found in the hypervisor_callback() function in the

Linux kernel provided by the kernel-xen package. This could cause a denial
of service of a 32-bit guest if an application running in that guest
accesses a certain memory location in the kernel. (CVE-2009-1758, Moderate)

• a flaw was found in the AGPGART driver. The agp_generic_alloc_page() and

agp_generic_alloc_pages() functions did not zero out the memory pages they
allocate, which may later be available to user-space processes. This flaw
could possibly lead to an information leak. (CVE-2009-1192, Low)

Bug fixes:

• a race in the NFS client between destroying cached access rights and

unmounting an NFS file system could have caused a system crash. "Busy
inodes" messages may have been logged. (BZ#498653)

• nanosleep() could sleep several milliseconds less than the specified time

on Intel Itanium(r)-based systems. (BZ#500349)

• LEDs for disk drives in AHCI mode may have displayed a fault state when

there were no faults. (BZ#500120)

• ptrace_do_wait() reported tasks were stopped each time the process doing

the trace called wait(), instead of reporting it once. (BZ#486945)

• epoll_wait() may have caused a system lockup and problems for

applications. (BZ#497322)

• missing capabilities could possibly allow users with an fsuid other than

0 to perform actions on some file system types that would otherwise be
prevented. (BZ#497271)

• on NFS mounted file systems, heavy write loads may have blocked

nfs_getattr() for long periods, causing commands that use stat(2), such as
ls, to hang. (BZ#486926)

• in rare circumstances, if an application performed multiple O_DIRECT

reads per virtual memory page and also performed fork(2), the buffer
storing the result of the I/O may have ended up with invalid data.
(BZ#486921)

• when using GFS2, gfs2_quotad may have entered an uninterpretable sleep

state. (BZ#501742)

• with this update, get_random_int() is more random and no longer uses a

common seed value, reducing the possibility of predicting the values
returned. (BZ#499783)

• the "-fwrapv" flag was added to the gcc build options to prevent gcc from

optimizing away wrapping. (BZ#501751)

• a kernel panic when enabling and disabling iSCSI paths. (BZ#502916)
• using the Broadcom NetXtreme BCM5704 network device with the tg3 driver

caused high system load and very bad performance. (BZ#502837)

• "/proc/[pid]/maps" and "/proc/[pid]/smaps" can only be read by processes

able to use the ptrace() call on a given process; however, certain
information from "/proc/[pid]/stat" and "/proc/[pid]/wchan" could be used
to reconstruct memory maps. (BZ#499546)

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 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/docs/DOC-11259

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 5.3 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.3 ia64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.3 i386
• Red Hat Enterprise Linux Server - AUS 5.3 x86_64
• Red Hat Enterprise Linux Server - AUS 5.3 ia64
• Red Hat Enterprise Linux Server - AUS 5.3 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 5.3 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 5.3 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 486921 - Corruption on ext3/xfs with O_DIRECT and unaligned user buffers
• BZ - 486926 - [RHEL5.2] nfs_getattr() hangs during heavy write workloads
• BZ - 486945 - waitpid() reports stopped process more than once
• BZ - 491572 - CVE-2009-1072 kernel: nfsd should drop CAP_MKNOD for non-root
• BZ - 494275 - CVE-2009-1439 kernel: cifs: memory overwrite when saving nativeFileSystem field during mount
• BZ - 496572 - CVE-2009-1633 kernel: cifs: fix potential buffer overruns when converting unicode strings sent by server
• BZ - 497020 - CVE-2009-1192 kernel: agp: zero pages before sending to userspace
• BZ - 497322 - crm #1896100 port epoll_wait fix from RHSA-2008-0665 to RHEL 5
• BZ - 498653 - fault in iget() - suspected race between nfs_access_cache_shrinker() and umount - Ref.: Bug #433249
• BZ - 499546 - kernel: proc: avoid information leaks to non-privileged processes [rhel-5.3.z]
• BZ - 499783 - kernel: random: make get_random_int() more random [rhel-5.3.z]
• BZ - 500120 - Problem with drive status leds after update to 2.6.18-128.el5
• BZ - 500297 - CVE-2009-1630 kernel: nfs: fix NFS v4 client handling of MAY_EXEC in nfs_permission
• BZ - 500349 - RHEL5.3.z LTP nanosleep02 Test Case Failure on Fujitsu Machine
• BZ - 500945 - CVE-2009-1758 kernel: xen: local denial of service
• BZ - 501742 - GFS2: gfs2_quotad in uninterruptible sleep while idle
• BZ - 501751 - kernel should be built with -fwrapv [rhel-5.3.z]
• BZ - 502837 - BCM5704 NIC results in CPU 100%SI , sluggish system performance
• BZ - 502916 - kernel BUG at drivers/scsi/libiscsi.c:301!

CVEs

• CVE-2009-1439
• CVE-2009-1192
• CVE-2009-1072
• CVE-2009-1633
• CVE-2009-1630
• CVE-2009-1758
• CVE-2009-3238

References