Critical kernel security update: vulnerability fixes CVE-2016-7910, CVE-2016-7911 (and other), new kernel 2.6.32-042stab120.11

This update provides a new Virtuozzo 6.0 kernel 2.6.32-042stab120.11 based on the Red Hat Enterprise Linux 6.8 kernel 2.6.32-642.6.1.el6. The new kernel provides security and stability fixes.
Vulnerability id: CVE-2016-1583
Stack overflow via ecryptfs and /proc/$pid/environ. It was found that stacking a file system over procfs in the Linux kernel could lead to a kernel stack overflow due to deep nesting, as demonstrated by mounting ecryptfs over procfs and creating a recursion by mapping /proc/environ. An unprivileged, local user could potentially use this flaw to escalate their privileges on the system.

Vulnerability id: CVE-2016-6828
Use after free in tcp_xmit_retransmit_queue. A use after free vulnerability was found in tcp_xmit_retransmit_queue and other tcp_* functions. This condition could allow an attacker to send an incorrect selective acknowledgment to existing connections, possibly resetting a connection.

Vulnerability id: CVE-2016-7910
block: fix use-after-free in seq file. Use-after-free vulnerability in the disk_seqf_stop function in block/genhd.c in the Linux kernel before 4.7.1 allows local users to gain privileges by leveraging the execution of a certain stop operation even if the corresponding start operation had failed.

Vulnerability id: CVE-2016-7911
block: fix use-after-free in sys_ioprio_get(). Race condition in the get_task_ioprio function in block/ioprio.c in the Linux kernel before 4.6.6 allows local users to gain privileges or cause a denial of service (use-after-free) via a crafted ioprio_get system call.