CVE-2021-3493

Published: 15 April 2021

The overlayfs implementation in the linux kernel did not properly validate with respect to user namespaces the setting of file capabilities on files in an underlying file system. Due to the combination of unprivileged user namespaces along with a patch carried in the Ubuntu kernel to allow unprivileged overlay mounts, an attacker could use this to gain elevated privileges.

From the Ubuntu security team

It was discovered that the overlayfs implementation in the Linux kernel did not properly validate the application of file system capabilities with respect to user namespaces. A local attacker could use this to gain elevated privileges.

Priority

High

CVSS 3 base score: 7.8

Status

Package Release Status
linux
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Not vulnerable
(5.11.0-11.12)
Ubuntu 20.10 (Groovy Gorilla)
Released (5.8.0-50.56)
Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-72.80)
Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-142.146)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.4.0-209.241)
Ubuntu 14.04 ESM (Trusty Tahr) Needs triage

Patches:
Introduced by 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Fixed by 7c03e2cda4a584cadc398e8f6641ca9988a39d52
linux-aws
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Not vulnerable
(5.11.0-1003.3)
Ubuntu 20.10 (Groovy Gorilla)
Released (5.8.0-1030.32)
Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-1045.47)
Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1099.106)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.4.0-1127.141)
Ubuntu 14.04 ESM (Trusty Tahr)
Released (4.4.0-1091.95)
linux-aws-5.0
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Ignored
(superseded by linux-aws-5.3)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-aws-5.3
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Ignored
(superseded by linux-aws-5.4)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-aws-5.4
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.4.0-1045.47~18.04.1)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-aws-hwe
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Does not exist

Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.15.0-1099.106~16.04.1)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-azure
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Not vulnerable
(5.11.0-1002.2)
Ubuntu 20.10 (Groovy Gorilla)
Released (5.8.0-1029.31)
Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-1046.48)
Ubuntu 18.04 LTS (Bionic Beaver) Ignored
(superseded by linux-azure-5.3)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.15.0-1113.126~16.04.1)
Ubuntu 14.04 ESM (Trusty Tahr)
Released (4.15.0-1113.126~14.04.1)
linux-azure-4.15
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1113.126)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-azure-5.3
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Ignored
(superseded by linux-azure-5.4)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-azure-5.4
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.4.0-1046.48~18.04.1)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-azure-edge
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Ignored
(superseded by linux-azure-5.3)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-dell300x
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1017.21)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-gcp
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Not vulnerable
(5.11.0-1003.3)
Ubuntu 20.10 (Groovy Gorilla)
Released (5.8.0-1028.29)
Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-1042.45)
Ubuntu 18.04 LTS (Bionic Beaver) Ignored
(superseded by linux-gcp-5.3)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.15.0-1098.111~16.04.1)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-gcp-4.15
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1098.111)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-gcp-5.3
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Ignored
(superseded by linux-gcp-5.4)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-gcp-5.4
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.4.0-1042.45~18.04.1)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-gcp-edge
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Ignored
(superseded by linux-gcp-5.3)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-gke
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Not vulnerable

Ubuntu 18.04 LTS (Bionic Beaver) Does not exist

Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-gke-4.15
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Ignored
(was needs-triage now end-of-life)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-gke-5.0
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Ignored
(was needs-triage now end-of-life)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-gke-5.3
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.3.0-1042.45)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-gke-5.4
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.4.0-1042.44~18.04.1)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-gkeop
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-1014.15)
Ubuntu 18.04 LTS (Bionic Beaver) Does not exist

Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-gkeop-5.4
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.4.0-1014.15~18.04.1)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-hwe
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.3.0-73.69)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.15.0-142.146~16.04.1)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-hwe-5.4
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.4.0-72.80~18.04.1)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-hwe-5.8
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa)
Released (5.8.0-50.56~20.04.1)
Ubuntu 18.04 LTS (Bionic Beaver) Does not exist

Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-hwe-edge
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Ignored
(superseded by linux-hwe-5.4)
Ubuntu 16.04 ESM (Xenial Xerus) Ignored
(superseded by linux-hwe)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-kvm
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Not vulnerable
(5.11.0-1003.3)
Ubuntu 20.10 (Groovy Gorilla)
Released (5.8.0-1024.26)
Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-1038.39)
Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1090.92)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.4.0-1092.101)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-lts-trusty
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Does not exist

Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-lts-xenial
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Does not exist

Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr)
Released (4.4.0-209.241~14.04.1)
linux-oem
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Ignored
(was needs-triage now end-of-life)
Ubuntu 16.04 ESM (Xenial Xerus) Ignored
(superseded by linux-hwe)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-oem-5.10
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa)
Released (5.10.0-1022.23)
Ubuntu 18.04 LTS (Bionic Beaver) Does not exist

Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-oem-5.6
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa)
Released (5.6.0-1054.58)
Ubuntu 18.04 LTS (Bionic Beaver) Does not exist

Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-oem-osp1
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Ignored
(was needs-triage now end-of-life)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-oracle
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Not vulnerable
(5.11.0-1002.2)
Ubuntu 20.10 (Groovy Gorilla)
Released (5.8.0-1026.27)
Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-1043.46)
Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1070.78)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.15.0-1070.78~16.04.1)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-oracle-5.0
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Ignored
(superseded by linux-oracle-5.3)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-oracle-5.3
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Ignored
(superseded by linux-oracle-5.4)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-oracle-5.4
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.4.0-1043.46~18.04.1)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-raspi
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Not vulnerable
(5.11.0-1003.3)
Ubuntu 20.10 (Groovy Gorilla)
Released (5.8.0-1021.24)
Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-1034.37)
Ubuntu 18.04 LTS (Bionic Beaver) Does not exist

Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-raspi-5.4
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.4.0-1034.37~18.04.1)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-raspi2
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Ignored
(replaced by linux-raspi)
Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1084.89)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.4.0-1151.162)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-raspi2-5.3
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.3.0-1039.41)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-riscv
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Not vulnerable
(5.11.0-1004.4)
Ubuntu 20.10 (Groovy Gorilla)
Released (5.8.0-22.24)
Ubuntu 20.04 LTS (Focal Fossa) Ignored
(superseded by generic focal kernel)
Ubuntu 18.04 LTS (Bionic Beaver) Does not exist

Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-snapdragon
Launchpad, Ubuntu, Debian
Upstream
Released (5.11~rc1)
Ubuntu 21.04 (Hirsute Hippo) Does not exist

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1101.110)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.4.0-1155.165)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Notes

AuthorNote
sbeattie
issue is specific to Ubuntu or any other distribution that
patched the kernel to allow unprivileged overlay mounts, prior to
the 5.11 commit (459c7c565ac36b) that permits it upstream.

References