Updated kernel packages that fix one security issue and two bugs are now available for Red Hat Enterprise Linux 5.3 Extended Update Support. The Red Hat Security Response Team has rated this update as having important security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.
The kernel packages contain the Linux kernel, the core of any Linux operating system. This update fixes the following security issue: * a use-after-free flaw was found in the tcp_rcv_state_process() function in the Linux kernel TCP/IP protocol suite implementation. If a system using IPv6 had the IPV6_RECVPKTINFO option set on a listening socket, a remote attacker could send an IPv6 packet to that system, causing a kernel panic (denial of service). (CVE-2010-1188, Important) This update also fixes the following bugs: * a memory leak occurred when reading files on an NFS file system that was mounted with the "noac" option, causing memory to slowly be consumed. Unmounting the file system did not free the memory. With this update, the memory is correctly freed, which resolves this issue. (BZ#588221) * the RHSA-2009:0225 update fixed a bug where, in some cases, on systems with the kdump service enabled, pressing Alt+SysRq+C to trigger a crash resulted in a system hang; therefore, the system did not restart and boot the dump-capture kernel as expected; no vmcore file was logged; and the following message was displayed on the console: BUG: warning at arch/[arch]/kernel/crash.c:[xxx]/nmi_shootdown_cpus() (Not tainted) The RHSA-2009:0225 update resolved this issue by not calling printk() during a crash. It was later discovered that this fix did not resolve the issue in all cases, since there was one condition where printk() was still being called: at a warning condition inside the mdelay() call. This update replaces mdelay() calls with udelay(), where such a warning condition does not exist, which fully resolves this issue, allowing Alt+SysRq+C to work as expected. (BZ#588211) 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.