RHSA-2014:0740 - Security Advisory

Topic

Updated kernel packages that fix three security issues and several bugs are
now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having
Important security impact. Common Vulnerability Scoring System (CVSS) base
scores, which give detailed severity ratings, are available for each
vulnerability from the CVE links in the References section.

Description

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

• A flaw was found in the way the Linux kernel's floppy driver handled user

space provided data in certain error code paths while processing FDRAWCMD
IOCTL commands. A local user with write access to /dev/fdX could use this
flaw to free (using the kfree() function) arbitrary kernel memory.
(CVE-2014-1737, Important)

• It was found that the Linux kernel's floppy driver leaked internal kernel

memory addresses to user space during the processing of the FDRAWCMD IOCTL
command. A local user with write access to /dev/fdX could use this flaw to
obtain information about the kernel heap arrangement. (CVE-2014-1738, Low)

Note: A local user with write access to /dev/fdX could use these two flaws
(CVE-2014-1737 in combination with CVE-2014-1738) to escalate their
privileges on the system.

• A NULL pointer dereference flaw was found in the rds_ib_laddr_check()

function in the Linux kernel's implementation of Reliable Datagram Sockets
(RDS). A local, unprivileged user could use this flaw to crash the system.
(CVE-2013-7339, Moderate)

Red Hat would like to thank Matthew Daley for reporting CVE-2014-1737 and
CVE-2014-1738.

This update also fixes the following bugs:

• A bug in the futex system call could result in an overflow when passing

a very large positive timeout. As a consequence, the FUTEX_WAIT operation
did not work as intended and the system call was timing out immediately.
A backported patch fixes this bug by limiting very large positive timeouts
to the maximal supported value. (BZ#1091832)

• A new Linux Security Module (LSM) functionality related to the setrlimit

hooks should produce a warning message when used by a third party module
that could not cope with it. However, due to a programming error, the
kernel could print this warning message when a process was setting rlimits
for a different process, or if rlimits were modified by another than the
main thread even though there was no incompatible third party module. This
update fixes the relevant code and ensures that the kernel handles this
warning message correctly. (BZ#1092869)

• Previously, the kernel was unable to detect KVM on system boot if the

Hyper-V emulation was enabled. A patch has been applied to ensure that
both KVM and Hyper-V hypervisors are now correctly detected during system
boot. (BZ#1094152)

• A function in the RPC code responsible for verifying whether cached

credentials match the current process did not perform the check correctly.
The code checked only whether the groups in the current process
credentials appear in the same order as in the cached credentials but did
not ensure that no other groups are present in the cached credentials. As
a consequence, when accessing files in NFS mounts, a process with the same
UID and GID as the original process but with a non-matching group list
could have been granted an unauthorized access to a file, or under certain
circumstances, the process could have been wrongly prevented from
accessing the file. The incorrect test condition has been fixed and the
problem can no longer occur. (BZ#1095062)

• When being under heavy load, some Fibre Channel storage devices, such as

Hitachi and HP Open-V series, can send a logout (LOGO) message to the
host system. However, due to a bug in the lpfc driver, this could result
in a loss of active paths to the storage and the paths could not be
recovered without manual intervention. This update corrects the lpfc
driver to ensure automatic recovery of the lost paths to the storage in
this scenario. (BZ#1096061)

All kernel users are advised to upgrade to these updated packages, which
contain backported patches to correct these issues. The system must be
rebooted for this update to take effect.

Solution

Before applying this update, make sure all previously released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to use the
Red Hat Network to apply this update are available at
https://access.redhat.com/site/articles/11258

To install kernel packages manually, use "rpm -ivh [package]". Do not use
"rpm -Uvh" as that will remove the running kernel binaries from your
system. You may use "rpm -e" to remove old kernels after determining that
the new kernel functions properly on your system.

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 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 Power, big endian 5 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 1079214 - CVE-2013-7339 kernel: net: rds: dereference of a NULL device in rds_ib_laddr_check()
• BZ - 1094299 - CVE-2014-1737 CVE-2014-1738 kernel: block: floppy: privilege escalation via FDRAWCMD floppy ioctl command

CVEs

• CVE-2013-7339
• CVE-2014-1737
• CVE-2014-1738

References

• https://access.redhat.com/security/updates/classification/#important