7.8 - RHSA-2009:1106

Problem Description:

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.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Desktop (v. 5 client) - i386, noarch, x86_64 Red Hat Enterprise Linux (v. 5 server) - i386, ia64, noarch, ppc, s390x, x86_64

3. 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®-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.

4. 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

5. Bugs fixed (http://bugzilla.redhat.com/):

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