Scientific Linux Security Update : kernel on SL5.x i386/x86_64
Low Nessus Plugin ID 71305
SynopsisThe remote Scientific Linux host is missing one or more security updates.
Description- An information leak flaw was found in the way the Xen hypervisor handled error conditions when reading guest memory during certain guest-originated operations, such as port or memory mapped I/O writes. A privileged user in a fully-virtualized guest could use this flaw to leak hypervisor stack memory to a guest. (CVE-2013-4355, Moderate)
This update also fixes the following bugs :
- A previous fix to the kernel did not contain a memory barrier in the percpu_up_write() function. Consequently, under certain circumstances, a race condition could occur leading to memory corruption and a subsequent kernel panic. This update introduces a new memory barrier pair, light_mb() and heavy_mb(), for per-CPU basis read and write semaphores (percpu-rw- semaphores) ensuring that the race condition can no longer occur. In addition, the read path performance of 'percpu-rw-semaphores' has been improved.
- Due to a bug in the tg3 driver, systems that had the Wake-on-LAN (WOL) feature enabled on their NICs could not have been woken up from suspension or hibernation using WOL. A missing pci_wake_from_d3() function call has been added to the tg3 driver, which ensures that WOL functions properly by setting the PME_ENABLE bit.
- Due to an incorrect test condition in the mpt2sas driver, the driver was unable to catch failures to map a SCSI scatter-gather list. The test condition has been corrected so that the mpt2sas driver now handles SCSI scatter-gather mapping failures as expected.
- A previous patch to the kernel introduced the 'VLAN tag re-insertion' workaround to resolve a problem with incorrectly handled VLAN-tagged packets with no assigned VLAN group while the be2net driver was in promiscuous mode. However, this solution led to packet corruption and a subsequent kernel oops if such a processed packed was a GRO packet. Therefore, a patch has been applied to restrict VLAN tag re-insertion only to non-GRO packets.
The be2net driver now processes VLAN-tagged packets with no assigned VLAN group correctly in this situation.
The system must be rebooted for this update to take effect.
SolutionUpdate the affected packages.