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redhatRedHatRHSA-2009:1466
HistorySep 29, 2009 - 12:00 a.m.

(RHSA-2009:1466) Important: kernel security and bug fix update

2009-09-2900:00:00
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19

5.9 Medium

CVSS2

Access Vector

LOCAL

Access Complexity

MEDIUM

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

PARTIAL

Availability Impact

COMPLETE

AV:L/AC:M/Au:N/C:P/I:P/A:C

0.001 Low

EPSS

Percentile

18.1%

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

This update includes backported fixes for two security issues. These issues
only affected users of Red Hat Enterprise Linux 5.3 Extended Update Support
as they have already been addressed for users of Red Hat Enterprise Linux 5
in the 5.4 update, RHSA-2009:1243.

In accordance with the support policy, future security updates to Red Hat
Enterprise Linux 5.3 Extended Update Support will only include issues of
critical security impact.

This update fixes the following security issues:

  • it was discovered that, when executing a new process, the clear_child_tid
    pointer in the Linux kernel is not cleared. If this pointer points to a
    writable portion of the memory of the new program, the kernel could corrupt
    four bytes of memory, possibly leading to a local denial of service or
    privilege escalation. (CVE-2009-2848, Important)

  • a flaw was found in the way the do_sigaltstack() function in the Linux
    kernel copies the stack_t structure to user-space. On 64-bit machines, this
    flaw could lead to a four-byte information leak. (CVE-2009-2847, Moderate)

This update also fixes the following bugs:

  • a regression was found in the SCSI retry logic: SCSI mode select was not
    retried when retryable errors were encountered. In Device-Mapper Multipath
    environments, this could cause paths to fail, or possibly prevent
    successful failover. (BZ#506905)

  • the gcc flag “-fno-delete-null-pointer-checks” was added to the kernel
    build options. This prevents gcc from optimizing out NULL pointer checks
    after the first use of a pointer. NULL pointer bugs are often exploited by
    attackers, and keeping these checks is considered a safety measure.
    (BZ#515468)

  • due to incorrect APIC timer calibration, a system hang could have
    occurred while booting certain systems. This incorrect timer calibration
    could have also caused the system time to become faster or slower. With
    this update, it is still possible for APIC timer calibration issues to
    occur; however, a clear warning is now provided if they do. (BZ#521237)

  • gettimeofday() experienced poor performance (which caused performance
    problems for applications using gettimeofday()) when running on hypervisors
    that use hardware assisted virtualization. With this update, MFENCE/LFENCE
    is used instead of CPUID for gettimeofday() serialization, which resolves
    this issue. (BZ#523280)

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.

5.9 Medium

CVSS2

Access Vector

LOCAL

Access Complexity

MEDIUM

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

PARTIAL

Availability Impact

COMPLETE

AV:L/AC:M/Au:N/C:P/I:P/A:C

0.001 Low

EPSS

Percentile

18.1%