Important: kernel

Issue Overview:

Race condition in the store_int_with_restart() function in cpu/mcheck/mce.c:
A race condition in the store_int_with_restart() function in arch/x86/kernel/cpu/mcheck/mce.c in the Linux kernel allows local users to cause a denial of service (panic) by leveraging root access to write to the check_interval file in a /sys/devices/system/machinecheck/machinecheck<cpu number> directory. (CVE-2018-7995)

Out-of-bounds write via userland offsets in ebt_entry struct in netfilter/ebtables.c:
A flaw was found in the Linux kernel’s implementation of 32-bit syscall interface for bridging. This allowed a privileged user to arbitrarily write to a limited range of kernel memory. (CVE-2018-1068)

A flaw was found in the Linux kernel’s skcipher component, which affects the skcipher_recvmsg function. Attackers using a specific input can lead to a privilege escalation.(CVE-2017-13215)

The do_get_mempolicy() function in mm/mempolicy.c in the Linux kernel allows local users to hit a use-after-free bug via crafted system calls and thus cause a denial of service (DoS) or possibly have unspecified other impact. Due to the nature of the flaw, privilege escalation cannot be fully ruled out.(CVE-2018-10675)

A flaw was found in Linux kernel’s KVM virtualization subsystem. The VMX code does not restore the GDT.LIMIT to the previous host value, but instead sets it to 64KB. With a corrupted GDT limit a host’s userspace code has an ability to place malicious entries in the GDT, particularly to the per-cpu variables. An attacker can use this to escalate their privileges.(CVE-2018-10901)

Affected Packages:

kernel

Note:

This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.

Issue Correction:
Run yum update kernel to update the kernel and reboot your instance to start the new kernel

New Packages:

src:  
    kernel-4.14.33-59.34.amzn2.src  
  
x86_64:  
    kernel-4.14.33-59.34.amzn2.x86_64  
    kernel-headers-4.14.33-59.34.amzn2.x86_64  
    kernel-debuginfo-common-x86_64-4.14.33-59.34.amzn2.x86_64  
    perf-4.14.33-59.34.amzn2.x86_64  
    perf-debuginfo-4.14.33-59.34.amzn2.x86_64  
    python-perf-4.14.33-59.34.amzn2.x86_64  
    python-perf-debuginfo-4.14.33-59.34.amzn2.x86_64  
    kernel-tools-4.14.33-59.34.amzn2.x86_64  
    kernel-tools-devel-4.14.33-59.34.amzn2.x86_64  
    kernel-tools-debuginfo-4.14.33-59.34.amzn2.x86_64  
    kernel-devel-4.14.33-59.34.amzn2.x86_64  
    kernel-debuginfo-4.14.33-59.34.amzn2.x86_64  

Additional References

Red Hat: CVE-2017-13215, CVE-2018-10675, CVE-2018-1068, CVE-2018-10901, CVE-2018-7995

Mitre: CVE-2017-13215, CVE-2018-10675, CVE-2018-1068, CVE-2018-10901, CVE-2018-7995