CVE-2020-12656

Published: 05 May 2020

** DISPUTED ** gss_mech_free in net/sunrpc/auth_gss/gss_mech_switch.c in the rpcsec_gss_krb5 implementation in the Linux kernel through 5.6.10 lacks certain domain_release calls, leading to a memory leak. Note: This was disputed with the assertion that the issue does not grant any access not already available. It is a problem that on unloading a specific kernel module some memory is leaked, but loading kernel modules is a privileged operation. A user could also write a kernel module to consume any amount of memory they like and load that replicating the effect of this bug.

From the Ubuntu security team

It was discovered that the Kerberos SUNRPC GSS implementation in the Linux kernel did not properly deallocate memory on module unload. A local privileged attacker could possibly use this to cause a denial of service (memory exhaustion).

Priority

Negligible

CVSS 3 base score: 5.5

Status

Package Release Status
linux-oem-5.6
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa)
Released (5.6.0-1031.32)
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-5.8
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Not vulnerable
(5.8.0-23.24~20.04.1)
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-gke-5.4
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Not vulnerable
(5.4.0-1025.25~18.04.1)
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 (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Not vulnerable
(5.4.0-1001.1)
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 (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.3.0-64.58~18.04.1)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.15.0-115.116~16.04.1)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-45.49)
Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-115.116)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.4.0-186.216)
Ubuntu 14.04 ESM (Trusty Tahr) Ignored
(was needs-triage ESM criteria)
Patches:
Introduced by 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Fixed by d47a5dc2888fd1b94adf1553068b8dad76cec96c
Introduced by 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Fixed by 24c5efe41c29ee3e55bcf5a1c9f61ca8709622e8
linux-hwe-edge
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
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
(was needs-triage now end-of-life)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-lts-xenial
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
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) Ignored
(was needs-triage ESM criteria)
linux-lts-trusty
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
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-oem
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1094.104)
Ubuntu 16.04 ESM (Xenial Xerus) Ignored
(was needs-triage now end-of-life)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-oem-osp1
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.0.0-1065.70)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-kvm
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-1021.21)
Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1072.73)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.4.0-1077.84)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-aws
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-1022.22)
Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1080.84)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.4.0-1111.123)
Ubuntu 14.04 ESM (Trusty Tahr) Ignored
(was needs-triage ESM criteria)
linux-aws-5.0
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
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-aws-hwe
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
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 (4.15.0-1080.84~16.04.1)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-azure
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-1023.23)
Ubuntu 18.04 LTS (Bionic Beaver) Ignored
(was needs-triage now end-of-life)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.15.0-1093.103~16.04.1)
Ubuntu 14.04 ESM (Trusty Tahr)
Released (4.15.0-1093.103~14.04.1)
linux-azure-5.3
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
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-azure-edge
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
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-gcp
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-1022.22)
Ubuntu 18.04 LTS (Bionic Beaver) Ignored
(was needs-triage now end-of-life)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.15.0-1081.92~16.04.1)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-gcp-5.3
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
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-gcp-edge
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
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-4.15
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1067.70)
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 (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.0.0-1045.46)
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 (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-1022.22)
Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1051.55)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.15.0-1051.55~16.04.1)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-oracle-5.0
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
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-raspi2
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Ignored
(was needs-triage now end-of-life)
Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1068.72)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.4.0-1136.145)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-snapdragon
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1084.92)
Ubuntu 16.04 ESM (Xenial Xerus)
Released (4.4.0-1140.148)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-raspi2-5.3
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.3.0-1030.32~18.04.2)
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 (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.3.0-1032.34~18.04.1)
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 (5.8~rc1)
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-riscv
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-31.35)
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
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa)
Released (5.4.0-1016.17)
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-azure-4.15
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1093.103)
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 (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Ignored
(was pending [5.3.0-1032.34~18.04.2] now end-of-life)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-gcp-4.15
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (4.15.0-1081.92)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-hwe-5.4
Launchpad, Ubuntu, Debian
Upstream
Released (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.4.0-45.49~18.04.2)
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 (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.4.0-1016.17~18.04.1)
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 (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.4.0-1023.23~18.04.1)
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 (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.4.0-1022.22~18.04.1)
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 (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.4.0-1022.22~18.04.1)
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 (5.8~rc1)
Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.4.0-1022.22~18.04.1)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Notes

AuthorNote
sbeattie
upstream generally treats module unload as an unsafe
operation, which may explain a lack of progress in addressing the
issue.

References