Updated kernel packages that fix two security issues and three bugs are now available for Red Hat Enterprise Linux 5.4 Extended Update Support. 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.
The kernel packages contain the Linux kernel, the core of any Linux operating system. This update fixes the following security issues: * When an application has a stack overflow, the stack could silently overwrite another memory mapped area instead of a segmentation fault occurring, which could cause an application to execute arbitrary code, possibly leading to privilege escalation. It is known that the X Window System server can be used to trigger this flaw. (CVE-2010-2240, Important) * A miscalculation of the size of the free space of the initial directory entry in a directory leaf block was found in the Linux kernel Global File System 2 (GFS2) implementation. A local, unprivileged user with write access to a GFS2-mounted file system could perform a rename operation on that file system to trigger a NULL pointer dereference, possibly resulting in a denial of service or privilege escalation. (CVE-2010-2798, Important) Red Hat would like to thank the X.Org security team for reporting CVE-2010-2240, with upstream acknowledging Rafal Wojtczuk as the original reporter; and Grant Diffey of CenITex for reporting CVE-2010-2798. This update also fixes the following bugs: * Problems receiving network traffic correctly via a non-standard layer 3 protocol when using the ixgbe driver. This update corrects this issue. (BZ#618275) * A bug was found in the way the megaraid_sas driver (for SAS based RAID controllers) handled physical disks and management IOCTLs. All physical disks were exported to the disk layer, allowing an oops in megasas_complete_cmd_dpc() when completing the IOCTL command if a timeout occurred. One possible trigger for this bug was running "mkfs". This update resolves this issue by updating the megaraid_sas driver to version 4.31. (BZ#619363) * Previously, Message Signaled Interrupts (MSI) resulted in PCI bus writes to mask and unmask the MSI IRQ for a PCI device. These unnecessary PCI bus writes resulted in the serialization of MSIs, leading to poor performance on systems with high MSI load. This update adds a new kernel boot parameter, msi_nolock, which forgoes the PCI bus writes and allows for better simultaneous processing of MSIs. (BZ#621939) Users should upgrade to these updated packages, which contain backported patches to correct these issues. The system must be rebooted for this update to take effect.