USN-4876-1: Linux kernel vulnerabilities

Releases

• Ubuntu 16.04 ESM
• Ubuntu 14.04 ESM

Packages

• linux - Linux kernel
• linux-aws - Linux kernel for Amazon Web Services (AWS) systems
• linux-kvm - Linux kernel for cloud environments
• linux-lts-xenial - Linux hardware enablement kernel from Xenial for Trusty
• linux-raspi2 - Linux kernel for Raspberry Pi (V8) systems
• linux-snapdragon - Linux kernel for Qualcomm Snapdragon processors

Details

Olivier Benjamin and Pawel Wieczorkiewicz discovered a race condition the
Xen paravirt block backend in the Linux kernel, leading to a use-after-free
vulnerability. An attacker in a guest VM could use this to cause a denial
of service in the host OS. (CVE-2020-29569)

It was discovered that the Marvell WiFi-Ex device driver in the Linux
kernel did not properly validate ad-hoc SSIDs. A local attacker could use
this to cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2020-36158)

吴异 discovered that the NFS implementation in the Linux kernel did not
properly prevent access outside of an NFS export that is a subdirectory of
a file system. An attacker could possibly use this to bypass NFS access
restrictions. (CVE-2021-3178)

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 16.04

• linux-image-4.4.0-1089-kvm - 4.4.0-1089.98
• linux-image-4.4.0-1123-aws - 4.4.0-1123.137
• linux-image-4.4.0-1147-raspi2 - 4.4.0-1147.157
• linux-image-4.4.0-1151-snapdragon - 4.4.0-1151.161
• linux-image-4.4.0-204-generic - 4.4.0-204.236
• linux-image-4.4.0-204-generic-lpae - 4.4.0-204.236
• linux-image-4.4.0-204-lowlatency - 4.4.0-204.236
• linux-image-4.4.0-204-powerpc-e500mc - 4.4.0-204.236
• linux-image-4.4.0-204-powerpc-smp - 4.4.0-204.236
• linux-image-4.4.0-204-powerpc64-emb - 4.4.0-204.236
• linux-image-4.4.0-204-powerpc64-smp - 4.4.0-204.236
• linux-image-aws - 4.4.0.1123.128
• linux-image-generic - 4.4.0.204.210
• linux-image-generic-lpae - 4.4.0.204.210
• linux-image-kvm - 4.4.0.1089.87
• linux-image-lowlatency - 4.4.0.204.210
• linux-image-powerpc-e500mc - 4.4.0.204.210
• linux-image-powerpc-smp - 4.4.0.204.210
• linux-image-powerpc64-emb - 4.4.0.204.210
• linux-image-powerpc64-smp - 4.4.0.204.210
• linux-image-raspi2 - 4.4.0.1147.147
• linux-image-snapdragon - 4.4.0.1151.143
• linux-image-virtual - 4.4.0.204.210

Ubuntu 14.04

• linux-image-4.4.0-1087-aws - 4.4.0-1087.91
• linux-image-4.4.0-204-generic - 4.4.0-204.236~14.04.1
• linux-image-4.4.0-204-generic-lpae - 4.4.0-204.236~14.04.1
• linux-image-4.4.0-204-lowlatency - 4.4.0-204.236~14.04.1
• linux-image-4.4.0-204-powerpc-e500mc - 4.4.0-204.236~14.04.1
• linux-image-4.4.0-204-powerpc-smp - 4.4.0-204.236~14.04.1
• linux-image-4.4.0-204-powerpc64-emb - 4.4.0-204.236~14.04.1
• linux-image-4.4.0-204-powerpc64-smp - 4.4.0-204.236~14.04.1
• linux-image-aws - 4.4.0.1087.84
• linux-image-generic-lpae-lts-xenial - 4.4.0.204.178
• linux-image-generic-lts-xenial - 4.4.0.204.178
• linux-image-lowlatency-lts-xenial - 4.4.0.204.178
• linux-image-powerpc-e500mc-lts-xenial - 4.4.0.204.178
• linux-image-powerpc-smp-lts-xenial - 4.4.0.204.178
• linux-image-powerpc64-emb-lts-xenial - 4.4.0.204.178
• linux-image-powerpc64-smp-lts-xenial - 4.4.0.204.178
• linux-image-virtual-lts-xenial - 4.4.0.204.178

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

• CVE-2020-29569
• CVE-2021-3178
• CVE-2020-36158

Related notices

• USN-4749-1: linux-image-lowlatency-hwe-16.04-edge, linux-image-oracle-lts-18.04, linux-image-gcp, linux-image-4.15.0-1085-kvm, linux-image-gcp-lts-18.04, linux-snapdragon, linux-gcp-4.15, linux-image-gke, linux-image-4.15.0-136-generic-lpae, linux-dell300x, linux-image-4.15.0-1079-gke, linux-image-4.15.0-1065-oracle, linux-azure-4.15, linux, linux-image-lowlatency, linux-image-azure, linux-image-virtual-hwe-16.04-edge, linux-kvm, linux-image-azure-edge, linux-oracle, linux-image-generic, linux-image-dell300x, linux-image-virtual-hwe-16.04, linux-image-4.15.0-1108-azure, linux-image-4.15.0-1096-snapdragon, linux-image-aws-hwe, linux-image-generic-lpae, linux-image-generic-lpae-hwe-16.04, linux-image-oem, linux-azure, linux-image-snapdragon, linux-image-aws-lts-18.04, linux-image-lowlatency-hwe-16.04, linux-image-4.15.0-136-generic, linux-image-generic-hwe-16.04, linux-aws-hwe, linux-image-4.15.0-1093-gcp, linux-image-4.15.0-136-lowlatency, linux-image-raspi2, linux-image-azure-lts-18.04, linux-image-kvm, linux-gcp, linux-gke-4.15, linux-aws, linux-image-4.15.0-1012-dell300x, linux-image-4.15.0-1094-aws, linux-image-generic-lpae-hwe-16.04-edge, linux-image-oracle, linux-hwe, linux-raspi2, linux-image-4.15.0-1079-raspi2, linux-image-generic-hwe-16.04-edge, linux-image-virtual, linux-image-gke-4.15
• USN-4750-1: linux-image-5.4.0-1038-oracle, linux-image-gcp, linux-image-5.4.0-1029-raspi, linux-image-5.4.0-1033-kvm, linux-aws-5.4, linux-image-snapdragon-hwe-18.04-edge, linux-image-5.4.0-1010-gkeop, linux-image-snapdragon-hwe-18.04, linux-image-generic-hwe-18.04-edge, linux-image-raspi2-hwe-18.04, linux, linux-image-lowlatency, linux-image-lowlatency-hwe-18.04-edge, linux-image-raspi-hwe-18.04-edge, linux-image-azure, linux-image-lowlatency-hwe-18.04, linux-image-azure-edge, linux-image-virtual-hwe-18.04-edge, linux-oracle, linux-image-5.4.0-1037-gcp, linux-image-generic, linux-image-virtual-hwe-18.04, linux-image-gkeop, linux-image-5.4.0-1040-azure, linux-raspi, linux-image-generic-lpae, linux-image-5.4.0-1036-gke, linux-image-oem, linux-azure, linux-image-gke-5.4, linux-gkeop-5.4, linux-image-5.4.0-66-generic-lpae, linux-image-aws-edge, linux-raspi-5.4, linux-image-aws, linux-image-raspi, linux-hwe-5.4, linux-image-raspi2, linux-image-kvm, linux-gcp, linux-image-raspi-hwe-18.04, linux-aws, linux-image-5.4.0-1038-aws, linux-gkeop, linux-image-generic-hwe-18.04, linux-gke-5.4, linux-oracle-5.4, linux-azure-5.4, linux-image-gkeop-5.4, linux-image-raspi2-hwe-18.04-edge, linux-image-oem-osp1, linux-image-5.4.0-66-generic, linux-image-oracle, linux-image-5.4.0-66-lowlatency, linux-image-gcp-edge, linux-image-generic-lpae-hwe-18.04, linux-image-virtual, linux-image-generic-lpae-hwe-18.04-edge, linux-kvm, linux-gcp-5.4, linux-image-oracle-edge
• USN-4751-1: linux-image-lowlatency-hwe-20.04-edge, linux-image-5.8.0-1019-kvm, linux-image-gcp, linux-image-generic-64k-hwe-20.04-edge, linux-image-generic-64k, linux-image-gke, linux-image-lowlatency-hwe-20.04, linux-hwe-5.8, linux, linux-image-lowlatency, linux-image-5.8.0-1016-raspi-nolpae, linux-image-azure, linux-kvm, linux-image-virtual-hwe-20.04, linux-oracle, linux-image-5.8.0-1024-aws, linux-image-generic, linux-image-5.8.0-1016-raspi, linux-image-5.8.0-1021-oracle, linux-image-generic-64k-hwe-20.04, linux-raspi, linux-image-generic-lpae, linux-azure, linux-image-aws, linux-image-generic-hwe-20.04-edge, linux-image-raspi, linux-image-5.8.0-44-generic, linux-image-generic-lpae-hwe-20.04-edge, linux-image-virtual-hwe-20.04-edge, linux-image-kvm, linux-gcp, linux-image-5.8.0-1023-azure, linux-image-oem-20.04, linux-aws, linux-image-5.8.0-44-generic-lpae, linux-image-generic-hwe-20.04, linux-image-5.8.0-1023-gcp, linux-image-oracle, linux-image-5.8.0-44-lowlatency, linux-image-virtual, linux-image-raspi-nolpae, linux-image-generic-lpae-hwe-20.04, linux-image-5.8.0-44-generic-64k
• USN-4877-1: linux-image-lowlatency-hwe-16.04-edge, linux-image-oracle-lts-18.04, linux-image-gcp, linux-image-4.15.0-137-generic-lpae, linux-image-gcp-lts-18.04, linux-image-4.15.0-137-lowlatency, linux-snapdragon, linux-gcp-4.15, linux-image-gke, linux-image-4.15.0-1094-gcp, linux-image-4.15.0-1097-snapdragon, linux-dell300x, linux-image-4.15.0-1080-raspi2, linux-azure-4.15, linux-image-4.15.0-1095-aws, linux, linux-image-lowlatency, linux-image-4.15.0-137-generic, linux-image-azure, linux-image-4.15.0-1066-oracle, linux-image-virtual-hwe-16.04-edge, linux-image-azure-edge, linux-oracle, linux-image-generic, linux-image-dell300x, linux-image-virtual-hwe-16.04, linux-image-4.15.0-1086-kvm, linux-image-aws-hwe, linux-image-generic-lpae, linux-image-oem, linux-image-generic-lpae-hwe-16.04, linux-azure, linux-image-snapdragon, linux-image-aws-lts-18.04, linux-image-lowlatency-hwe-16.04, linux-image-generic-hwe-16.04, linux-aws-hwe, linux-image-raspi2, linux-image-azure-lts-18.04, linux-image-kvm, linux-gcp, linux-aws, linux-image-4.15.0-1013-dell300x, linux-image-generic-lpae-hwe-16.04-edge, linux-image-oracle, linux-hwe, linux-raspi2, linux-image-generic-hwe-16.04-edge, linux-image-virtual, linux-kvm, linux-image-4.15.0-1109-azure
• USN-4878-1: linux-image-gcp, linux-image-5.4.0-1039-aws, linux-aws-5.4, linux-image-5.4.0-67-generic, linux-image-snapdragon-hwe-18.04-edge, linux-image-snapdragon-hwe-18.04, linux-image-generic-hwe-18.04-edge, linux-image-raspi2-hwe-18.04, linux-image-5.4.0-1011-gkeop, linux, linux-image-lowlatency, linux-image-lowlatency-hwe-18.04-edge, linux-image-raspi-hwe-18.04-edge, linux-image-azure, linux-image-lowlatency-hwe-18.04, linux-image-azure-edge, linux-image-virtual-hwe-18.04-edge, linux-oracle, linux-image-generic, linux-image-virtual-hwe-18.04, linux-image-5.4.0-1034-kvm, linux-image-gkeop, linux-image-5.4.0-1041-azure, linux-raspi, linux-image-generic-lpae, linux-image-oem, linux-azure, linux-image-5.4.0-1039-oracle, linux-image-gke-5.4, linux-gkeop-5.4, linux-image-aws-edge, linux-raspi-5.4, linux-image-aws, linux-image-5.4.0-1038-gcp, linux-image-raspi, linux-hwe-5.4, linux-image-raspi2, linux-image-kvm, linux-gcp, linux-image-5.4.0-67-lowlatency, linux-image-raspi-hwe-18.04, linux-aws, linux-image-5.4.0-1037-gke, linux-gkeop, linux-image-generic-hwe-18.04, linux-gke-5.4, linux-oracle-5.4, linux-azure-5.4, linux-image-gkeop-5.4, linux-image-raspi2-hwe-18.04-edge, linux-image-oem-osp1, linux-image-oracle, linux-image-5.4.0-1030-raspi, linux-image-gcp-edge, linux-image-generic-lpae-hwe-18.04, linux-image-virtual, linux-image-generic-lpae-hwe-18.04-edge, linux-kvm, linux-gcp-5.4, linux-image-5.4.0-67-generic-lpae, linux-image-oracle-edge
• USN-4910-1: linux-image-lowlatency-hwe-20.04-edge, linux-image-5.8.0-49-generic-lpae, linux-image-gcp, linux-image-generic-64k-hwe-20.04-edge, linux-image-5.8.0-49-generic-64k, linux-image-generic-64k, linux-image-gke, linux-image-lowlatency-hwe-20.04, linux-hwe-5.8, linux, linux-image-lowlatency, linux-image-azure, linux-kvm, linux-image-virtual-hwe-20.04, linux-oracle, linux-image-generic, linux-image-5.8.0-1027-gcp, linux-image-5.8.0-1020-raspi-nolpae, linux-image-generic-64k-hwe-20.04, linux-raspi, linux-image-generic-lpae, linux-azure, linux-image-5.8.0-1025-oracle, linux-image-5.8.0-49-lowlatency, linux-image-5.8.0-1028-aws, linux-image-aws, linux-image-5.8.0-1020-raspi, linux-image-generic-hwe-20.04-edge, linux-image-raspi, linux-image-generic-lpae-hwe-20.04-edge, linux-image-5.8.0-1027-azure, linux-image-virtual-hwe-20.04-edge, linux-image-5.8.0-1023-kvm, linux-gcp, linux-image-kvm, linux-image-oem-20.04, linux-aws, linux-image-generic-hwe-20.04, linux-image-oracle, linux-image-virtual, linux-image-raspi-nolpae, linux-image-generic-lpae-hwe-20.04, linux-image-5.8.0-49-generic
• USN-4912-1: linux-oem-5.6, linux-image-5.6.0-1053-oem, linux-image-oem-20.04
• USN-4879-1: linux-image-lowlatency-hwe-20.04-edge, linux-image-5.8.0-1020-kvm, linux-image-gcp, linux-image-generic-64k-hwe-20.04-edge, linux-image-5.8.0-45-generic, linux-image-5.8.0-1024-azure, linux-image-generic-64k, linux-image-5.8.0-1025-aws, linux-image-gke, linux-image-lowlatency-hwe-20.04, linux-hwe-5.8, linux, linux-image-lowlatency, linux-image-5.8.0-1017-raspi-nolpae, linux-image-azure, linux-kvm, linux-image-virtual-hwe-20.04, linux-oracle, linux-image-generic, linux-image-5.8.0-1022-oracle, linux-image-generic-64k-hwe-20.04, linux-raspi, linux-image-generic-lpae, linux-azure, linux-image-5.8.0-45-generic-lpae, linux-image-aws, linux-image-generic-hwe-20.04-edge, linux-image-raspi, linux-image-generic-lpae-hwe-20.04-edge, linux-image-virtual-hwe-20.04-edge, linux-image-5.8.0-1017-raspi, linux-image-5.8.0-1024-gcp, linux-gcp, linux-image-5.8.0-45-generic-64k, linux-aws, linux-image-kvm, linux-image-oem-20.04, linux-image-generic-hwe-20.04, linux-image-oracle, linux-image-virtual, linux-image-raspi-nolpae, linux-image-generic-lpae-hwe-20.04, linux-image-5.8.0-45-lowlatency