RHSA-2008:0211 - Security Advisory

Topic

Updated kernel packages that fix various security issues and several bugs
are now available for Red Hat Enterprise Linux 3.

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)

• 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)

• a flaw was found when performing asynchronous input or output operations

on a FIFO special file. A local unprivileged user could use this flaw to
cause a kernel panic. (CVE-2007-5001, Important)

• a flaw was found in the way core dump files were created. If a local user

could get a root-owned process to dump a core file into a directory, which
the user has write access to, they could gain read access to that core
file. This could potentially grant unauthorized access to sensitive
information. (CVE-2007-6206, Moderate)

• a buffer overflow was found in the Linux kernel ISDN subsystem. A local

unprivileged user could use this flaw to cause a denial of service.
(CVE-2007-6151, Moderate)

• a race condition found in the mincore system core could allow a local

user to cause a denial of service (system hang). (CVE-2006-4814, Moderate)

• 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:

• a bug, which caused long delays when unmounting mounts containing a large

number of unused dentries, has been resolved.

• in the previous kernel packages, the kernel was unable to handle certain

floating point instructions on Itanium(R) architectures.

• on certain Intel CPUs, the Translation Lookaside Buffer (TLB) was not

flushed correctly, which caused machine check errors.

Red Hat Enterprise Linux 3 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 3 x86_64
• Red Hat Enterprise Linux Server 3 ia64
• Red Hat Enterprise Linux Server 3 i386
• Red Hat Enterprise Linux Workstation 3 x86_64
• Red Hat Enterprise Linux Workstation 3 ia64
• Red Hat Enterprise Linux Workstation 3 i386
• Red Hat Enterprise Linux Desktop 3 x86_64
• Red Hat Enterprise Linux Desktop 3 i386
• Red Hat Enterprise Linux for IBM z Systems 3 s390x
• Red Hat Enterprise Linux for IBM z Systems 3 s390
• Red Hat Enterprise Linux for Power, big endian 3 ppc

Fixes

• BZ - 306971 - CVE-2006-4814 kernel Race condition in mincore can cause "ps -ef" to hang
• BZ - 326251 - CVE-2007-5001 kernel asynchronous IO on a FIFO kernel panic
• BZ - 396861 - CVE-2007-6206 Issue with core dump owner
• BZ - 413731 - RHEL3: System hangs at unmount
• BZ - 425111 - CVE-2007-6151 I4L: fix isdn_ioctl memory issue
• BZ - 428961 - CVE-2008-0007 kernel: insufficient range checks in fault handlers with mremap
• BZ - 437312 - CVE-2008-1367 Kernel doesn't clear DF for signal handlers
• BZ - 439754 - CVE-2008-1375 kernel: race condition in dnotify (local DoS, local roothole possible)
• 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-2006-4814
• CVE-2007-6206
• CVE-2007-6151
• CVE-2007-5001
• CVE-2008-1669
• CVE-2008-0007
• CVE-2008-1367
• CVE-2008-1375

References

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