Protect yourself against future threats.
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===========================================================================
AUSCERT External Security Bulletin Redistribution
ESB-2021.3483
Linux kernel vulnerabilities
20 October 2021
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: kernel
Publisher: Ubuntu
Operating System: Ubuntu
Impact/Access: Root Compromise -- Existing Account
Execute Arbitrary Code/Commands -- Existing Account
Denial of Service -- Existing Account
Access Confidential Data -- Existing Account
Reduced Security -- Existing Account
Resolution: Patch/Upgrade
CVE Names: CVE-2021-42008 CVE-2021-40490 CVE-2021-38166
CVE-2021-3753 CVE-2021-3743 CVE-2021-3739
CVE-2021-3732 CVE-2020-3702
Reference: ESB-2021.3456
ESB-2021.3455
ESB-2021.3422
ESB-2021.3391
ESB-2021.3265
Original Bulletin:
https://ubuntu.com/security/notices/USN-5113-1
- --------------------------BEGIN INCLUDED TEXT--------------------
USN-5113-1: Linux kernel vulnerabilities
19 October 2021
Several security issues were fixed in the Linux kernel.
Releases
o Ubuntu 21.04
o Ubuntu 20.04 LTS
Packages
o linux - Linux kernel
o linux-aws - Linux kernel for Amazon Web Services (AWS) systems
o linux-aws-5.11 - Linux kernel for Amazon Web Services (AWS) systems
o linux-azure - Linux kernel for Microsoft Azure Cloud systems
o linux-azure-5.11 - Linux kernel for Microsoft Azure cloud systems
o linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
o linux-gcp-5.11 - Linux kernel for Google Cloud Platform (GCP) systems
o linux-hwe-5.11 - Linux hardware enablement (HWE) kernel
o linux-kvm - Linux kernel for cloud environments
o linux-raspi - Linux kernel for Raspberry Pi systems
Details
It was discovered that a race condition existed in the Atheros Ath9k WiFi
driver in the Linux kernel. An attacker could possibly use this to expose
sensitive information (WiFi network traffic). ( CVE-2020-3702 )
Alois Wohlschlager discovered that the overlay file system in the Linux
kernel did not restrict private clones in some situations. An attacker
could use this to expose sensitive information. ( CVE-2021-3732 )
It was discovered that the btrfs file system in the Linux kernel did not
properly handle removing a non-existent device id. An attacker with
CAP_SYS_ADMIN could use this to cause a denial of service. ( CVE-2021-3739 )
It was discovered that the Qualcomm IPC Router protocol implementation in
the Linux kernel did not properly validate metadata in some situations. A
local attacker could use this to cause a denial of service (system crash)
or expose sensitive information. ( CVE-2021-3743 )
It was discovered that the virtual terminal (vt) device implementation in
the Linux kernel contained a race condition in its ioctl handling that lead
to an out-of-bounds read vulnerability. A local attacker could possibly use
this to expose sensitive information. ( CVE-2021-3753 )
It was discovered that the BPF subsystem in the Linux kernel contained an
integer overflow in its hash table implementation. A local attacker could
use this to cause a denial of service (system crash) or possibly execute
arbitrary code. ( CVE-2021-38166 )
It was discovered that the ext4 file system in the Linux kernel contained a
race condition when writing xattrs to an inode. A local attacker could use
this to cause a denial of service or possibly gain administrative
privileges. ( CVE-2021-40490 )
It was discovered that the 6pack network protocol driver in the Linux
kernel did not properly perform validation checks. A privileged attacker
could use this to cause a denial of service (system crash) or execute
arbitrary code. ( CVE-2021-42008 )
Update instructions
The problem can be corrected by updating your system to the following package
versions:
Ubuntu 21.04
o linux-image-5.11.0-1021-raspi-nolpae - 5.11.0-1021.22
o linux-image-virtual - 5.11.0.38.39
o linux-image-generic-64k - 5.11.0.38.39
o linux-image-generic - 5.11.0.38.39
o linux-image-5.11.0-38-lowlatency - 5.11.0-38.42
o linux-image-5.11.0-38-generic-lpae - 5.11.0-38.42
o linux-image-aws - 5.11.0.1020.21
o linux-image-5.11.0-1020-azure - 5.11.0-1020.21
o linux-image-5.11.0-38-generic - 5.11.0-38.42
o linux-image-5.11.0-1018-kvm - 5.11.0-1018.19
o linux-image-azure - 5.11.0.1020.21
o linux-image-raspi-nolpae - 5.11.0.1021.19
o linux-image-oem-20.04 - 5.11.0.38.39
o linux-image-gke - 5.11.0.1021.21
o linux-image-gcp - 5.11.0.1021.21
o linux-image-5.11.0-1021-gcp - 5.11.0-1021.23
o linux-image-5.11.0-1020-aws - 5.11.0-1020.21
o linux-image-raspi - 5.11.0.1021.19
o linux-image-kvm - 5.11.0.1018.19
o linux-image-generic-lpae - 5.11.0.38.39
o linux-image-lowlatency - 5.11.0.38.39
o linux-image-5.11.0-38-generic-64k - 5.11.0-38.42
o linux-image-5.11.0-1021-raspi - 5.11.0-1021.22
Ubuntu 20.04
o linux-image-virtual-hwe-20.04 - 5.11.0.38.42~20.04.17
o linux-image-5.11.0-38-lowlatency - 5.11.0-38.42~20.04.1
o linux-image-5.11.0-38-generic-lpae - 5.11.0-38.42~20.04.1
o linux-image-aws - 5.11.0.1020.21~20.04.19
o linux-image-5.11.0-1020-azure - 5.11.0-1020.21~20.04.1
o linux-image-lowlatency-hwe-20.04 - 5.11.0.38.42~20.04.17
o linux-image-generic-hwe-20.04 - 5.11.0.38.42~20.04.17
o linux-image-gcp - 5.11.0.1021.23~20.04.20
o linux-image-5.11.0-1021-gcp - 5.11.0-1021.23~20.04.1
o linux-image-5.11.0-1020-aws - 5.11.0-1020.21~20.04.2
o linux-image-azure-edge - 5.11.0.1020.21~20.04.19
o linux-image-generic-lpae-hwe-20.04 - 5.11.0.38.42~20.04.17
o linux-image-5.11.0-38-generic - 5.11.0-38.42~20.04.1
o linux-image-generic-64k-hwe-20.04 - 5.11.0.38.42~20.04.17
o linux-image-5.11.0-38-generic-64k - 5.11.0-38.42~20.04.1
After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.
References
o CVE-2021-42008
o CVE-2021-38166
o CVE-2021-40490
o CVE-2021-3739
o CVE-2021-3743
o CVE-2021-3753
o CVE-2021-3732
o CVE-2020-3702
Related notices
o USN-5096-1 : linux-oem-5.13, linux-image-oem-20.04c,
linux-image-5.13.0-1014-oem, linux-image-unsigned-5.13.0-1014-oem,
linux-buildinfo-5.13.0-1014-oem, linux-tools-5.13.0-1014-oem,
linux-oem-20.04c, linux-oem-5.13-headers-5.13.0-1014,
linux-oem-5.13-tools-host, linux-headers-5.13.0-1014-oem,
linux-modules-5.13.0-1014-oem, linux-oem-5.13-tools-5.13.0-1014,
linux-tools-oem-20.04c, linux-headers-oem-20.04c
o USN-5094-2 : linux-raspi2, linux-image-4.15.0-1096-raspi2,
linux-raspi2-tools-4.15.0-1096, linux-buildinfo-4.15.0-1096-raspi2,
linux-headers-raspi2, linux-tools-raspi2, linux-modules-4.15.0-1096-raspi2,
linux-tools-4.15.0-1096-raspi2, linux-headers-4.15.0-1096-raspi2,
linux-image-raspi2, linux-raspi2-headers-4.15.0-1096
o USN-5094-1 : linux-azure-edge, linux-headers-kvm, linux-image-azure,
linux-tools-lowlatency-hwe-16.04, linux-image-4.15.0-1100-kvm,
linux-image-oem, linux-headers-virtual-hwe-16.04-edge,
linux-buildinfo-4.15.0-1081-oracle, linux-headers-4.15.0-159-generic,
linux-tools-host, linux-signed-image-lowlatency-hwe-16.04-edge,
linux-snapdragon-tools-4.15.0-1113, linux-cloud-tools-common,
linux-buildinfo-4.15.0-159-lowlatency, linux-image-snapdragon,
linux-generic-lpae-hwe-16.04-edge, linux-modules-4.15.0-159-generic,
linux-cloud-tools-4.15.0-1112-aws, linux-modules-extra-4.15.0-1081-oracle,
linux-image-virtual, linux-azure-4.15-headers-4.15.0-1124,
linux-modules-extra-aws-hwe, linux-signed-image-lowlatency,
linux-cloud-tools-4.15.0-159-lowlatency,
linux-modules-4.15.0-1028-dell300x, linux-generic-lpae,
linux-headers-4.15.0-159-lowlatency, linux-modules-extra-4.15.0-1124-azure,
linux-tools-oem, linux-tools-4.15.0-1081-oracle,
linux-headers-generic-lpae, linux-modules-4.15.0-1113-snapdragon,
linux-virtual-hwe-16.04-edge, linux-signed-lowlatency-hwe-16.04,
linux-image-extra-virtual-hwe-16.04-edge, linux-tools-common,
linux-gcp-4.15-tools-4.15.0-1109, linux-headers-4.15.0-1113-snapdragon,
linux-image-unsigned-4.15.0-159-generic, linux-headers-oracle-lts-18.04,
linux-gcp-4.15, linux-cloud-tools-lowlatency-hwe-16.04-edge,
linux-signed-image-azure-edge, linux-modules-4.15.0-1124-azure,
linux-headers-4.15.0-1100-kvm, linux-aws-headers-4.15.0-1112,
linux-buildinfo-4.15.0-1112-aws, linux-lowlatency-hwe-16.04-edge,
linux-cloud-tools-lowlatency-hwe-16.04, linux-signed-azure,
linux-headers-aws-hwe, linux-tools-gcp,
linux-image-unsigned-4.15.0-1081-oracle, linux-tools-azure-lts-18.04,
linux-tools-lowlatency, linux-cloud-tools-generic-hwe-16.04-edge,
linux-signed-oracle-lts-18.04, linux-headers-generic-hwe-16.04,
linux-tools-aws-hwe, linux-tools-virtual-hwe-16.04-edge,
linux-signed-lowlatency, linux-tools-generic-hwe-16.04-edge,
linux-headers-azure-edge, linux-image-gcp, linux-modules-4.15.0-1112-aws,
linux-tools-gke, linux-tools-oracle-lts-18.04, linux-image-generic,
linux-aws-tools-4.15.0-1112, linux-tools-generic-lpae-hwe-16.04-edge,
linux-image-oracle, linux-image-4.15.0-1081-oracle,
linux-signed-azure-lts-18.04, linux-image-azure-edge,
linux-image-generic-lpae-hwe-16.04, linux-cloud-tools-4.15.0-159,
linux-tools-4.15.0-159-generic-lpae,
linux-modules-extra-4.15.0-159-generic,
linux-signed-image-generic-hwe-16.04, linux-virtual, linux-gcp,
linux-modules-extra-4.15.0-1109-gcp,
linux-buildinfo-4.15.0-159-generic-lpae, linux-image-oracle-lts-18.04,
linux-tools-gcp-lts-18.04, linux-image-4.15.0-1028-dell300x,
linux-source-4.15.0, linux-snapdragon, linux-modules-extra-azure-edge,
linux-buildinfo-4.15.0-1028-dell300x, linux-kvm, linux-headers-dell300x,
linux-cloud-tools-4.15.0-1124-azure, linux-headers-gcp-lts-18.04,
linux-image-4.15.0-159-generic-lpae, linux-lowlatency,
linux-aws-cloud-tools-4.15.0-1112, linux-cloud-tools-virtual-hwe-16.04,
linux-modules-extra-4.15.0-1112-aws, linux-modules-extra-aws-lts-18.04,
linux-headers-4.15.0-1109-gcp, linux-image-extra-virtual-hwe-16.04,
linux-signed-image-oem, linux-tools-4.15.0-159-generic,
linux-generic-lpae-hwe-16.04, linux-tools-4.15.0-1028-dell300x,
linux-cloud-tools-azure-lts-18.04, linux-source,
linux-hwe-tools-4.15.0-159, linux-signed-image-oracle-lts-18.04,
linux-modules-extra-gke, linux-image-generic-lpae, linux-virtual-hwe-16.04,
linux-tools-4.15.0-159-lowlatency, linux-oem,
linux-signed-image-lowlatency-hwe-16.04, linux-tools-generic-lpae,
linux-modules-4.15.0-159-generic-lpae,
linux-cloud-tools-virtual-hwe-16.04-edge, linux-gcp-tools-4.15.0-1109,
linux-oracle, linux-gke, linux-headers-lowlatency-hwe-16.04-edge,
linux-image-unsigned-4.15.0-159-lowlatency, linux-tools-4.15.0-1100-kvm,
linux-tools-4.15.0-1113-snapdragon, linux-aws-hwe-cloud-tools-4.15.0-1112,
linux-signed-image-azure, linux-headers-virtual-hwe-16.04, linux-aws,
linux-image-generic-hwe-16.04-edge, linux-image-lowlatency, linux-libc-dev,
linux-oracle-lts-18.04, linux-signed-azure-edge, linux-aws-hwe,
linux-aws-edge, linux-signed-generic, linux-kvm-headers-4.15.0-1100,
linux-image-azure-lts-18.04, linux-headers-4.15.0-1124-azure,
linux-buildinfo-4.15.0-1100-kvm, linux-cloud-tools-generic,
linux-image-4.15.0-1112-aws, linux-image-4.15.0-1124-azure,
linux-modules-extra-azure-lts-18.04,
linux-buildinfo-4.15.0-1113-snapdragon, linux-azure-headers-4.15.0-1124,
linux-tools-generic-hwe-16.04, linux-headers-generic, linux-headers-gcp,
linux-lowlatency-hwe-16.04, linux, linux-modules-4.15.0-1100-kvm,
linux-gcp-4.15-headers-4.15.0-1109, linux-headers-lowlatency-hwe-16.04,
linux-image-virtual-hwe-16.04, linux-headers-virtual,
linux-image-4.15.0-1113-snapdragon, linux-image-generic-hwe-16.04,
linux-modules-extra-gcp, linux-image-virtual-hwe-16.04-edge,
linux-tools-4.15.0-1112-aws, linux-modules-4.15.0-159-lowlatency,
linux-dell300x, linux-oracle-tools-4.15.0-1081, linux-signed-oem,
linux-headers-4.15.0-159, linux-dell300x-headers-4.15.0-1028,
linux-modules-extra-gcp-lts-18.04, linux-signed-image-oracle,
linux-image-generic-lpae-hwe-16.04-edge,
linux-image-unsigned-4.15.0-1028-dell300x,
linux-headers-4.15.0-1028-dell300x, linux-aws-lts-18.04,
linux-signed-generic-hwe-16.04, linux-headers-lowlatency,
linux-signed-lowlatency-hwe-16.04-edge, linux-tools-kvm,
linux-generic-hwe-16.04, linux-tools-virtual-hwe-16.04,
linux-buildinfo-4.15.0-159-generic, linux-image-lowlatency-hwe-16.04,
linux-aws-hwe-tools-4.15.0-1112, linux-buildinfo-4.15.0-1124-azure,
linux-modules-4.15.0-1109-gcp, linux-cloud-tools-4.15.0-159-generic,
linux-cloud-tools-generic-hwe-16.04, linux-cloud-tools-virtual,
linux-tools-aws-lts-18.04, linux-hwe, linux-snapdragon-headers-4.15.0-1113,
linux-gcp-lts-18.04, linux-azure-lts-18.04, linux-cloud-tools-lowlatency,
linux-tools-lowlatency-hwe-16.04-edge, linux-image-kvm,
linux-image-dell300x, linux-headers-snapdragon,
linux-oracle-headers-4.15.0-1081, linux-tools-dell300x,
linux-headers-oracle, linux-image-4.15.0-1109-gcp,
linux-image-4.15.0-159-generic, linux-tools-azure-edge, linux-generic,
linux-headers-generic-lpae-hwe-16.04, linux-modules-4.15.0-1081-oracle,
linux-cloud-tools-azure, linux-azure, linux-buildinfo-4.15.0-1109-gcp,
linux-generic-hwe-16.04-edge, linux-image-lowlatency-hwe-16.04-edge,
linux-doc, linux-image-unsigned-4.15.0-1124-azure,
linux-azure-tools-4.15.0-1124, linux-image-aws-lts-18.04,
linux-tools-generic-lpae-hwe-16.04, linux-image-extra-virtual,
linux-tools-oracle, linux-tools-generic, linux-headers-azure-lts-18.04,
linux-crashdump, linux-kvm-tools-4.15.0-1100,
linux-image-4.15.0-159-lowlatency, linux-cloud-tools-azure-edge,
linux-azure-4.15-tools-4.15.0-1124, linux-image-unsigned-4.15.0-1109-gcp,
linux-dell300x-tools-4.15.0-1028, linux-headers-4.15.0-159-generic-lpae,
linux-image-gcp-lts-18.04, linux-image-gke, linux-modules-extra-azure,
linux-tools-4.15.0-159, linux-signed-generic-hwe-16.04-edge,
linux-headers-4.15.0-1112-aws, linux-tools-snapdragon, linux-headers-gke,
linux-tools-virtual, linux-headers-aws-lts-18.04,
linux-headers-generic-hwe-16.04-edge, linux-signed-image-azure-lts-18.04,
linux-headers-generic-lpae-hwe-16.04-edge,
linux-azure-4.15-cloud-tools-4.15.0-1124, linux-gcp-headers-4.15.0-1109,
linux-signed-image-generic-hwe-16.04-edge, linux-signed-image-generic,
linux-headers-oem, linux-signed-oracle, linux-headers-azure,
linux-tools-4.15.0-1124-azure, linux-headers-4.15.0-1081-oracle,
linux-azure-4.15, linux-tools-azure, linux-hwe-cloud-tools-4.15.0-159,
linux-tools-4.15.0-1109-gcp, linux-image-aws-hwe,
linux-azure-cloud-tools-4.15.0-1124
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