Synopsis: Important: kernel security, bug fix, and enhancement update
Issue Date: 2012-12-04
CVE Numbers: CVE-2012-2372
* A race condition in the way asynchronous I/O and fallocate() interacted
when using ext4 could allow a local, unprivileged user to obtain random
data from a deleted file. (CVE-2012-4508, Important)
* A flaw in the way the Xen hypervisor implementation range checked guest
provided addresses in the XENMEM_exchange hypercall could allow a
malicious, para-virtualized guest administrator to crash the hypervisor or,
potentially, escalate their privileges, allowing them to execute arbitrary
code at the hypervisor level. (CVE-2012-5513, Important)
* A flaw in the Reliable Datagram Sockets (RDS) protocol implementation
could allow a local, unprivileged user to cause a denial of service.
* A race condition in the way access to inet->opt ip_options was
synchronized in the Linux kernel’s TCP/IP protocol suite implementation.
Depending on the network facing applications running on the system, a
remote attacker could possibly trigger this flaw to cause a denial of
service. A local, unprivileged user could use this flaw to cause a denial
of service regardless of the applications the system runs. (CVE-2012-3552,
* The Xen hypervisor implementation did not properly restrict the period
values used to initialize per VCPU periodic timers. A privileged guest user
could cause an infinite loop on the physical CPU. If the watchdog were
enabled, it would detect said loop and panic the host system.
* A flaw in the way the Xen hypervisor implementation handled
set_p2m_entry() error conditions could allow a privileged,
fully-virtualized guest user to crash the hypervisor. (CVE-2012-4537,
* Previously, the interrupt handlers of the qla2xxx driver could clear
pending interrupts right after the IRQ lines were attached during system
start-up. Consequently, the kernel could miss the interrupt that reported
completion of the link initialization, and the qla2xxx driver then failed
to detect all attached LUNs. With this update, the qla2xxx driver has been
modified to no longer clear interrupt bits after attaching the IRQ lines.
The driver now correctly detects all attached LUNs as expected.
* The Ethernet channel bonding driver reported the MII (Media Independent
Interface) status of the bond interface in 802.3ad mode as being up even
though the MII status of all of the slave devices was down. This could pose
a problem if the MII status of the bond interface was used to determine if
failover should occur. With this update, the agg_device_up() function has
been added to the bonding driver, which allows the driver to report the
link status of the bond interface correctly, that is, down when all of its
slaves are down, in the 802.3ad mode.
* This update backports several changes from the latest upstream version of
the bnx2x driver. The most important change, the remote-fault link
detection feature, allows the driver to periodically scan the physical link
layer for remote faults. If the physical link appears to be up and a fault
is detected, the driver indicates that the link is down. When the fault is
cleared, the driver indicates that the link is up again.
* The INET socket interface has been modified to send a warning message
when the ip_options structure is allocated directly by a third-party module
using the kmalloc() function.
The system must be rebooted for this update to take effect.
– Scientific Linux Development Team