Important: kernel security and bug fix update

Updated kernel packages that resolve several security issues and fix
various 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.

[Updated 12th November 2008]
The original packages distributed with this errata had a bug which
prevented the Xen kernel booting on older hardware. We have updated the
packages to correct this bug.

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

* the Xen implementation did not prevent applications running in a
para-virtualized guest from modifying CR4 TSC. This could cause a local
denial of service. (CVE-2007-5907, Important)

* Tavis Ormandy reported missing boundary checks in the Virtual Dynamic
Shared Objects (vDSO) implementation. This could allow a local unprivileged
user to cause a denial of service or escalate privileges. (CVE-2008-3527,
Important)

* the do_truncate() and generic_file_splice_write() functions did not clear
the setuid and setgid bits. This could allow a local unprivileged user to
obtain access to privileged information. (CVE-2008-4210, CVE-2008-3833,
Important)

* a flaw was found in the Linux kernel splice implementation. This could
cause a local denial of service when there is a certain failure in the
add_to_page_cache_lru() function. (CVE-2008-4302, Important)

* a flaw was found in the Linux kernel when running on AMD64 systems.
During a context switch, EFLAGS were being neither saved nor restored. This
could allow a local unprivileged user to cause a denial of service.
(CVE-2006-5755, Low)

* a flaw was found in the Linux kernel virtual memory implementation. This
could allow a local unprivileged user to cause a denial of service.
(CVE-2008-2372, Low)

* an integer overflow was discovered in the Linux kernel Datagram
Congestion Control Protocol (DCCP) implementation. This could allow a
remote attacker to cause a denial of service. By default, remote DCCP is
blocked by SELinux. (CVE-2008-3276, Low)

In addition, these updated packages fix the following bugs:

* random32() seeding has been improved.

* in a multi-core environment, a race between the QP async event-handler
and the destro_qp() function could occur. This led to unpredictable results
during invalid memory access, which could lead to a kernel crash.

* a format string was omitted in the call to the request_module() function.

* a stack overflow caused by an infinite recursion bug in the binfmt_misc
kernel module was corrected.

* the ata_scsi_rbuf_get() and ata_scsi_rbuf_put() functions now check for
scatterlist usage before calling kmap_atomic().

* a sentinel NUL byte was added to the device_write() function to ensure
that lspace.name is NUL-terminated.

* in the character device driver, a range_is_allowed() check was added to
the read_mem() and write_mem() functions. It was possible for an
illegitimate application to bypass these checks, and access /dev/mem beyond
the 1M limit by calling mmap_mem() instead. Also, the parameters of
range_is_allowed() were changed to cleanly handle greater than 32-bits of
physical address on 32-bit architectures.

* some of the newer Nehalem-based systems declare their CPU DSDT entries as
type "Alias". During boot, this caused an "Error attaching device data"
message to be logged.

* the evtchn event channel device lacked locks and memory barriers. This
has led to xenstore becoming unresponsive on the Itanium® architecture.

* sending of gratuitous ARP packets in the Xen frontend network driver is
now delayed until the backend signals that its carrier status has been
processed by the stack.

* on forcedeth devices, whenever setting ethtool parameters for link speed,
the device could stop receiving interrupts.

* the CIFS 'forcedirectio' option did not allow text to be appended to files.

* the gettimeofday() function returned a backwards time on Intel® 64.

* residual-count corrections during UNDERRUN handling were added to the
qla2xxx driver.

* the fix for a small quirk was removed for certain Adaptec controllers for
which it caused problems.

* the "xm trigger init" command caused a domain panic if a userland
application was running on a guest on the Intel® 64 architecture.

Users of kernel should upgrade to these updated packages, which contain
backported patches to correct these issues.

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

377561 - CVE-2007-5907 kernel-xen 3.1.1 does not prevent modification of the CR4 TSC from applications (DoS possible)
452666 - CVE-2008-2372 kernel: Reinstate ZERO_PAGE optimization in 'get_user_pages()' and fix XIP
457718 - CVE-2006-5755 kernel: local denial of service due to NT bit leakage
458021 - kernel: random32: seeding improvement [rhel-5.2.z]
458759 - kernel: dlm: dlm/user.c input validation fixes [rhel-5.2.z]
458781 - LTC44618-Race possibility between QP async handler and destroy_qp()
459226 - CVE-2008-3276 Linux kernel dccp_setsockopt_change() integer overflow
459461 - kernel: cpufreq: fix format string bug [rhel-5.2.z]
459464 - kernel: binfmt_misc.c: avoid potential kernel stack overflow [rhel-5.2.z]
460251 - CVE-2008-3527 kernel: missing boundary checks in syscall/syscall32_nopage()
460638 - [REG][5.3] The system crashed by the NULL pointer access with kmap_atomic() of ata_scsi_rbuf_get().
460858 - kernel: devmem: add range_is_allowed() check to mmap_mem() [rhel-5.2.z]
460868 - RHEL5.2 ACPI core bug
461099 - evtchn device lacks lock and barriers
461457 - Coordinate gratuitous ARP with backend network status
461894 - nVidia MCP55 MCP55 Ethernet (rev a3) not functional on kernel 2.6.18-53.1.4
462434 - CVE-2008-4302 kernel: splice: fix bad unlock_page() in error case
462591 - CIFS option forcedirectio fails to allow the appending of text to files.
462860 - RHEL5.3: Fix time of gettimeofday() going backward (EM64T) (*)
463661 - CVE-2008-4210 kernel: open() call allows setgid bit when user is not in new file's group
464450 - CVE-2008-3833 kernel: remove SUID when splicing into an inode
465741 - [QLogic 5.2.z bug] qla2xxx - Additional residual-count corrections during UNDERRUN handling.
466427 - Significant regression in time() performance
466885 - [aacraid 5.2.z] aac_srb: aac_fib_send failed with status 8195
467105 - xm trigger <domain> init causes kernel panic.

https://www.redhat.com/security/data/cve/CVE-2006-5755.html
https://www.redhat.com/security/data/cve/CVE-2007-5907.html
https://www.redhat.com/security/data/cve/CVE-2008-2372.html
https://www.redhat.com/security/data/cve/CVE-2008-3276.html
https://www.redhat.com/security/data/cve/CVE-2008-3527.html
https://www.redhat.com/security/data/cve/CVE-2008-3833.html
https://www.redhat.com/security/data/cve/CVE-2008-4210.html
https://www.redhat.com/security/data/cve/CVE-2008-4302.html
http://www.redhat.com/security/updates/classification/#important