Red Hat 6.1 Important: RHSA-2012:1430-01 DoS Risk Fix in Kernel

The kernel packages contain the Linux kernel, the core of any Linux operating system.
This update fixes the following security issue:
* A flaw was found in the way socket buffers (skb) requiring TSO (TCP segment offloading) were handled by the sfc driver. If the skb did not fit within the minimum-size of the transmission queue, the network card could repeatedly reset itself. A remote attacker could use this flaw to cause a denial of service. (CVE-2012-3412, Important)
Red Hat would like to thank Ben Hutchings of Solarflare (tm) for reporting this issue.
This update also fixes the following bugs:
* In the hpet_next_event() function, an interrupt could have occurred between the read and write of the HPET (High Precision Event Timer) and the value of HPET_COUNTER was then beyond that being written to the comparator (HPET_Tn_CMP). Consequently, the timers were overdue for up to several minutes. Now, a comparison is performed between the value of the counter and the comparator in the HPET code. If the counter is beyond the comparator, the "-ETIME" error code is returned, which fixes this bug. (BZ#855280)
* Traffic to the NFS server could trigger a kernel oops in the svc_tcp_clear_pages() function. The source code has been modified, and the kernel oops no longer occurs in this scenario. (BZ#856104)
* A kernel oops occurred in the nf_nat code when a bogus pointer was dereferenced in the nf_conn_nat structure. Consequently, if Source Network Address Translation (SNAT) was performed, incorrect information could be received by other CTS (Clear to Send) signals. A conntrack entry is now placed in the source hash after SNAT has been completed, which prevents the described problems. (BZ#865714)
Users should upgrade to these updated packages, which contain backported patches to resolve these issues. The system must be rebooted for this update to take effect.