RHSA-2008:0612 - Security Advisory

Topic

Updated kernel packages that fix various 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.

These updated packages fix the following security issues:

• a possible kernel memory leak was found in the Linux kernel Simple

Internet Transition (SIT) INET6 implementation. This could allow a local
unprivileged user to cause a denial of service. (CVE-2008-2136, Important)

• a flaw was found in the Linux kernel setrlimit system call, when setting

RLIMIT_CPU to a certain value. This could allow a local unprivileged user
to bypass the CPU time limit. (CVE-2008-1294, Moderate)

• multiple NULL pointer dereferences were found in various Linux kernel

network drivers. These drivers were missing checks for terminal validity,
which could allow privilege escalation. (CVE-2008-2812, Moderate)

These updated packages fix the following bugs:

• the GNU libc stub resolver is a minimal resolver that works with Domain

Name System (DNS) servers to satisfy requests from applications for names.
The GNU libc stub resolver did not specify a source UDP port, and therefore
used predictable port numbers. This could have made DNS spoofing attacks
easier.

The Linux kernel has been updated to implement random UDP source ports
where none are specified by an application. This allows applications, such
as those using the GNU libc stub resolver, to use random UDP source ports,
helping to make DNS spoofing attacks harder.

• when using certain hardware, a bug in UART_BUG_TXEN may have caused

incorrect hardware detection, causing data flow to "/dev/ttyS1" to hang.

• a 50-75% drop in NFS server rewrite performance, compared to Red Hat

Enterprise Linux 4.6, has been resolved.

• due a bug in the fast userspace mutex code, while one thread fetched a

pointer, another thread may have removed it, causing the first thread to
fetch the wrong pointer, possibly causing a system crash.

• on certain Hitachi hardware, removing the "uhci_hcd" module caused a

kernel oops, and the following error:

BUG: warning at arch/ia64/kernel/iosapic.c:1001/iosapic_unregister_intr()

Even after the "uhci_hcd" module was reloaded, there was no access to USB
devices. As well, on systems that have legacy interrupts,
"acpi_unregister_gsi" incorrectly called "iosapci_unregister_intr()",
causing warning messages to be logged.

• when a page was mapped with mmap(), and "PROT_WRITE" was the only

"prot" argument, the first read of that page caused a segmentation fault.
If the page was read after it was written to, no fault occurred. This was
incompatible with the Red Hat Enterprise Linux 4 behavior.

• due to a NULL pointer dereference in powernowk8_init(), a panic may

have occurred.

• certain error conditions handled by the bonding sysfs interface could

have left rtnl_lock() unbalanced, either by locking and returning without
unlocking, or by unlocking when it did not lock, possibly causing a
"kernel: RTNL: assertion failed at net/core/fib_rules.c" error.

• the kernel currently expects a maximum of six Machine Check Exception

(MCE) banks to be exposed by a CPU. Certain CPUs have 7 or more, which may
have caused the MCE to be incorrectly reported.

• a race condition in UNIX domain sockets may have caused recv() to return

zero. For clusters, this may have caused unexpected failovers.

• msgrcv() frequently returned an incorrect "ERESTARTNOHAND (514)" error

number.

• on certain Intel Itanium-based systems, when kdump was configured to halt

the system after a dump operation, after the "System halted." output, the
kernel continued to output endless "soft lockup" messages.

Red Hat Enterprise Linux 5 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 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 5.2 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.2 ia64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.2 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 5.2 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 5.2 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 437114 - CVE-2008-1294 kernel: setrlimit(RLIMIT_CPUINFO) with zero value doesn't inherit properly across children
• BZ - 443071 - [Stratus 5.2.z][1/2] ttyS1 lost interrupt and it stops transmitting [rhel-5.2.z]
• BZ - 446031 - CVE-2008-2136 kernel: sit memory leak
• BZ - 448685 - 50-75 % drop in nfs-server rewrite performance compared to rhel 4.6+ [rhel-5.2.z]
• BZ - 450336 - Kernel crash on futex [rhel-5.2.z]
• BZ - 450337 - [RHEL5] BUG: warning at arch/ia64/kernel/iosapic.c:1001/iosapic_unregiste
• BZ - 450758 - mmap() with PROT_WRITE on RHEL5 incompatible with RHEL4.
• BZ - 450866 - RHEL 5.3 NULL pointer dereferenced in powernowk8_init
• BZ - 451939 - bonding driver can leave rtnl_lock unbalanced
• BZ - 451941 - RHEL 5.3 extend MCE banks support for Dunnington, Nehalem, and beyond
• BZ - 452231 - [RHEL5.1] In unix domain sockets, recv() may incorrectly return zero
• BZ - 453419 - CVE-2008-2812 kernel: NULL ptr dereference in multiple network drivers due to missing checks in tty code
• BZ - 454566 - kernel: randomize udp port allocation
• BZ - 455256 - [Stratus 5.2.z][2/2] ttyS1 lost interrupt and it stops transmitting
• BZ - 455278 - The msgrcv() syscall fails with error number 514 (ERESTARTNOHAND).
• BZ - 456117 - [REG][5.3] Soft lockup is detected

CVEs

• CVE-2008-2136
• CVE-2008-2812
• CVE-2008-1294

References

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