Medium: kernel

Issue Overview:

The Linux kernel before 4.4.1 allows local users to bypass file-descriptor limits and cause a denial of service (memory consumption) by sending each descriptor over a UNIX socket before closing it, related to net/unix/af_unix.c and net/unix/garbage.c. (CVE-2013-4312)

A race condition in the tty_ioctl function in drivers/tty/tty_io.c in the Linux kernel through 4.4.1 was found that allows local users to obtain sensitive information from kernel memory or cause a denial of service (use-after-free and system crash) by making a TIOCGETD ioctl call during processing of a TIOCSETD ioctl call. (CVE-2016-0723)

A privilege-escalation vulnerability was discovered in the Linux kernel built with User Namespace (CONFIG_USER_NS) support. The flaw occurred when the ptrace() system call was used on a root-owned process to enter a user namespace. A privileged namespace user could exploit this flaw to potentially escalate their privileges on the system, outside the original namespace. (CVE-2015-8709)

net/sctp/sm_sideeffect.c in the Linux kernel before 4.3 does not properly manage the relationship between a lock and a socket, which allows local users to cause a denial of service (deadlock) via a crafted sctp_accept call. (CVE-2015-8767)

Affected Packages:

kernel

Issue Correction:
Run yum clean all followed by yum update kernel to update your system. You will need to reboot your system in order for the new kernel to be running.

New Packages:

i686:  
    kernel-tools-debuginfo-4.1.17-22.30.amzn1.i686  
    kernel-devel-4.1.17-22.30.amzn1.i686  
    perf-4.1.17-22.30.amzn1.i686  
    perf-debuginfo-4.1.17-22.30.amzn1.i686  
    kernel-tools-4.1.17-22.30.amzn1.i686  
    kernel-headers-4.1.17-22.30.amzn1.i686  
    kernel-debuginfo-common-i686-4.1.17-22.30.amzn1.i686  
    kernel-debuginfo-4.1.17-22.30.amzn1.i686  
    kernel-4.1.17-22.30.amzn1.i686  
    kernel-tools-devel-4.1.17-22.30.amzn1.i686  
  
noarch:  
    kernel-doc-4.1.17-22.30.amzn1.noarch  
  
src:  
    kernel-4.1.17-22.30.amzn1.src  
  
x86_64:  
    kernel-debuginfo-4.1.17-22.30.amzn1.x86_64  
    kernel-devel-4.1.17-22.30.amzn1.x86_64  
    kernel-4.1.17-22.30.amzn1.x86_64  
    kernel-tools-4.1.17-22.30.amzn1.x86_64  
    perf-debuginfo-4.1.17-22.30.amzn1.x86_64  
    kernel-tools-devel-4.1.17-22.30.amzn1.x86_64  
    kernel-debuginfo-common-x86_64-4.1.17-22.30.amzn1.x86_64  
    kernel-tools-debuginfo-4.1.17-22.30.amzn1.x86_64  
    perf-4.1.17-22.30.amzn1.x86_64  
    kernel-headers-4.1.17-22.30.amzn1.x86_64  

Additional References

Red Hat: CVE-2013-4312, CVE-2015-8709, CVE-2015-8767, CVE-2016-0723

Mitre: CVE-2013-4312, CVE-2015-8709, CVE-2015-8767, CVE-2016-0723