CVE-2020-16120

Published: 13 October 2020

It was discovered when using shiftfs with overlayfs and fuse in an unprivileged user namespace, it was possible to receive the data of files that were not readable by the mounter before setting up permissions. It was later found that by only using unprivileged user namespaces and overlayfs, it was possible to have a file not readable by the unprivileged user to be copied to a mountpoint controlled by such user, like a removable device.

From the Ubuntu security team

Giuseppe Scrivano discovered that the overlay file system in the Linux kernel did not properly perform permission checks in some situations. A local attacker could possibly use this to bypass intended restrictions and gain read access to restricted files.

Priority

Medium

Status

Package Release Status
linux
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Needs triage

Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-51.56)
Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-121.123)
Ubuntu 16.04 LTS (Xenial Xerus) Needs triage

Ubuntu 14.04 ESM (Trusty Tahr) Needs triage

Ubuntu 12.04 ESM (Precise Pangolin) Needs triage

linux-aws
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Needs triage

Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-1028.29)
Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1086.91)
Ubuntu 16.04 LTS (Xenial Xerus) Needs triage

Ubuntu 14.04 ESM (Trusty Tahr) Needs triage

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-aws-5.0
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Needs triage

Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-aws-5.3
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Needs triage

Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-aws-5.4
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.4.0-1028.29~18.04.1)
Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-aws-hwe
Launchpad, Ubuntu, Debian
Upstream Needs triage

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 LTS (Xenial Xerus)
Released (4.15.0-1085.90~16.04.1)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-azure
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Needs triage

Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-1031.32)
Ubuntu 18.04 LTS (Bionic Beaver) Needs triage

Ubuntu 16.04 LTS (Xenial Xerus)
Released (4.15.0-1098.109~16.04.1)
Ubuntu 14.04 ESM (Trusty Tahr)
Released (4.15.0-1098.109~14.04.1)
Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-azure-4.15
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1099.110)
Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-azure-5.3
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Needs triage

Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-azure-5.4
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.4.0-1031.32~18.04.1)
Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-azure-edge
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Needs triage

Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-gcp
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Needs triage

Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-1028.29)
Ubuntu 18.04 LTS (Bionic Beaver) Needs triage

Ubuntu 16.04 LTS (Xenial Xerus)
Released (4.15.0-1086.98~16.04.1)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-gcp-4.15
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1086.98)
Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-gcp-5.3
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Needs triage

Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-gcp-5.4
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.4.0-1028.29~18.04.1)
Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-gcp-edge
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Needs triage

Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-gke-4.15
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1072.76)
Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-gke-5.0
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.0.0-1049.50)
Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-gke-5.3
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.3.0-1038.40)
Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-hwe
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.3.0-68.63)
Ubuntu 16.04 LTS (Xenial Xerus)
Released (4.15.0-120.122~16.04.1)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-hwe-5.4
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.4.0-51.56~18.04.1)
Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-hwe-edge
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Needs triage

Ubuntu 16.04 LTS (Xenial Xerus) Needs triage

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-kvm
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Needs triage

Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-1026.27)
Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1077.79)
Ubuntu 16.04 LTS (Xenial Xerus) Needs triage

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-lts-trusty
Launchpad, Ubuntu, Debian
Upstream Needs triage

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 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Needs triage

linux-lts-xenial
Launchpad, Ubuntu, Debian
Upstream Needs triage

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 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Needs triage

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-oem
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1099.109)
Ubuntu 16.04 LTS (Xenial Xerus) Needs triage

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-oem-5.6
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Needs triage

Ubuntu 18.04 LTS (Bionic Beaver) Does not exist

Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-oem-osp1
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.0.0-1069.75)
Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-oracle
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Needs triage

Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-1028.29)
Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1057.62)
Ubuntu 16.04 LTS (Xenial Xerus)
Released (4.15.0-1056.61~16.04.1)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-oracle-5.0
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Needs triage

Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-oracle-5.3
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Needs triage

Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-oracle-5.4
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.4.0-1028.29~18.04.1)
Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-raspi
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Needs triage

Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-1021.24)
Ubuntu 18.04 LTS (Bionic Beaver) Does not exist

Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-raspi-5.4
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.4.0-1021.24~18.04.1)
Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-raspi2
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Needs triage

Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1073.78)
Ubuntu 16.04 LTS (Xenial Xerus) Needs triage

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-raspi2-5.3
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.3.0-1035.37)
Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-riscv
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Needs triage

Ubuntu 20.04 LTS (Focal Fossa) Needs triage

Ubuntu 18.04 LTS (Bionic Beaver) Does not exist

Ubuntu 16.04 LTS (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

linux-snapdragon
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Does not exist

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1089.98)
Ubuntu 16.04 LTS (Xenial Xerus) Needs triage

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Ubuntu 12.04 ESM (Precise Pangolin) Does not exist

Notes

AuthorNote
sbeattie this issue most likely only has an impact on Ubuntu systems as it is dependent on both unprivileged user namespaces being enabled as well as a non-upstream patch that allows overlayfs mounts in user namespaces.

References

Bugs