ALAS2-2021-1719


Amazon Linux 2 Security Advisory: ALAS-2021-1719
Advisory Release Date: 2021-10-28 23:22 Pacific
Advisory Updated Date: 2021-11-04 18:04 Pacific
Severity: Important

Issue Overview:

A flaw was found in the Linux kernel. A corrupted timer tree caused the task wakeup to be missing in the timerqueue_add function in lib/timerqueue.c. This flaw allows a local attacker with special user privileges to cause a denial of service, slowing and eventually stopping the system while running OSP. The highest threat from this vulnerability is system availability. (CVE-2021-20317)

A race condition accessing file object in the Linux kernel OverlayFS subsystem was found in the way users do rename in specific way with OverlayFS. A local user could use this flaw to crash the system. (CVE-2021-20321)

A flaw use-after-free in the Linux kernel USB High Speed Mobile Devices functionality was found in the way user detaches USB device. A local user could use this flaw to crash the system or escalate their privileges on the system. (CVE-2021-37159)

A flaw was found in the Linux kernel. A memory leak in the ccp-ops crypto driver can allow attackers to cause a denial of service. This vulnerability is similar with the older CVE-2019-18808. The highest threat from this vulnerability is to system availability. (CVE-2021-3744)

A memory leak flaw was found in the Linux kernel's ccp_run_aes_gcm_cmd() function that allows an attacker to cause a denial of service. The vulnerability is similar to the older CVE-2019-18808. The highest threat from this vulnerability is to system availability. (CVE-2021-3764)

A flaw was found in the Linux kernel. The cBPF JIT compiler may produce machine code with incorrect branches. This flaw allows an unprivileged user to craft anomalous machine code, where the control flow is hijacked to execute arbitrary kernel code. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability. (CVE-2021-38300)

An out-of-bounds (OOB) memory write flaw was found in prealloc_elems_and_freelist in kernel/bpf/stackmap.c in the bpf in the Linux kernel. In this flaw, the multiplication to calculate the size could lead to an integer overflow which could allow a local attacker, with a special user privilege, to gain access to out-of-bounds memory leading to a system crash or a leak of internal kernel information. (CVE-2021-41864)


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 your system.

New Packages:
aarch64:
    kernel-4.14.252-195.481.amzn2.aarch64
    kernel-headers-4.14.252-195.481.amzn2.aarch64
    kernel-debuginfo-common-aarch64-4.14.252-195.481.amzn2.aarch64
    perf-4.14.252-195.481.amzn2.aarch64
    perf-debuginfo-4.14.252-195.481.amzn2.aarch64
    python-perf-4.14.252-195.481.amzn2.aarch64
    python-perf-debuginfo-4.14.252-195.481.amzn2.aarch64
    kernel-tools-4.14.252-195.481.amzn2.aarch64
    kernel-tools-devel-4.14.252-195.481.amzn2.aarch64
    kernel-tools-debuginfo-4.14.252-195.481.amzn2.aarch64
    kernel-devel-4.14.252-195.481.amzn2.aarch64
    kernel-debuginfo-4.14.252-195.481.amzn2.aarch64

i686:
    kernel-headers-4.14.252-195.481.amzn2.i686

src:
    kernel-4.14.252-195.481.amzn2.src

x86_64:
    kernel-4.14.252-195.481.amzn2.x86_64
    kernel-headers-4.14.252-195.481.amzn2.x86_64
    kernel-debuginfo-common-x86_64-4.14.252-195.481.amzn2.x86_64
    perf-4.14.252-195.481.amzn2.x86_64
    perf-debuginfo-4.14.252-195.481.amzn2.x86_64
    python-perf-4.14.252-195.481.amzn2.x86_64
    python-perf-debuginfo-4.14.252-195.481.amzn2.x86_64
    kernel-tools-4.14.252-195.481.amzn2.x86_64
    kernel-tools-devel-4.14.252-195.481.amzn2.x86_64
    kernel-tools-debuginfo-4.14.252-195.481.amzn2.x86_64
    kernel-devel-4.14.252-195.481.amzn2.x86_64
    kernel-debuginfo-4.14.252-195.481.amzn2.x86_64
    kernel-livepatch-4.14.252-195.481-1.0-0.amzn2.x86_64