CVE-2019-15794

Published: 08 November 2019

Overlayfs in the Linux kernel and shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, both replace vma->vm_file in their mmap handlers. On error the original value is not restored, and the reference is put for the file to which vm_file points. On upstream kernels this is not an issue, as no callers dereference vm_file following after call_mmap() returns an error. However, the aufs patchs change mmap_region() to replace the fput() using a local variable with vma_fput(), which will fput() vm_file, leading to a refcount underflow.

From the Ubuntu security team

Jann Horn discovered that the OverlayFS and ShiftFS Drivers in the Linux kernel did not properly handle reference counting during memory mapping operations when used in conjunction with AUFS. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code.

Priority

Medium

CVSS 3 base score: 6.7

Status

Package Release Status
linux
Launchpad, Ubuntu, Debian
Upstream Needed

Ubuntu 20.04 LTS (Focal Fossa) Not vulnerable
(5.4.0-9.12)
Ubuntu 18.04 LTS (Bionic Beaver) Not vulnerable
(4.13.0-16.19)
Ubuntu 16.04 ESM (Xenial Xerus) Not vulnerable
(4.2.0-16.19)
Ubuntu 14.04 ESM (Trusty Tahr) Ignored
(was needs-triage ESM criteria)
Patches:
Introduced by local-2019-15794-shift-break
Fixed by local-2019-15794-shift-fix
Introduced by local-2019-15794-ovl-break
Fixed by local-2019-15794-ovl-fix
linux-aws
Launchpad, Ubuntu, Debian
Upstream Needed

Ubuntu 20.04 LTS (Focal Fossa) Not vulnerable
(5.4.0-1005.5)
Ubuntu 18.04 LTS (Bionic Beaver) Not vulnerable
(4.15.0-1001.1)
Ubuntu 16.04 ESM (Xenial Xerus) Not vulnerable
(4.4.0-1001.10)
Ubuntu 14.04 ESM (Trusty Tahr) Ignored
(was needs-triage ESM criteria)
linux-aws-5.0
Launchpad, Ubuntu, Debian
Upstream Needed

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.0.0-1022.25~18.04.1)
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 Needed

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Does not exist

Ubuntu 16.04 ESM (Xenial Xerus) Not vulnerable
(4.15.0-1030.31~16.04.1)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-azure
Launchpad, Ubuntu, Debian
Upstream Needed

Ubuntu 20.04 LTS (Focal Fossa) Not vulnerable
(5.4.0-1006.6)
Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.0.0-1027.29~18.04.1)
Ubuntu 16.04 ESM (Xenial Xerus) Not vulnerable
(4.11.0-1009.9)
Ubuntu 14.04 ESM (Trusty Tahr) Ignored
(was needs-triage ESM criteria)
linux-azure-5.3
Launchpad, Ubuntu, Debian
Upstream Needed

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.3.0-1008.9~18.04.1)
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 Needed

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-gcp
Launchpad, Ubuntu, Debian
Upstream Needed

Ubuntu 20.04 LTS (Focal Fossa) Not vulnerable
(5.4.0-1005.5)
Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.0.0-1026.27~18.04.1)
Ubuntu 16.04 ESM (Xenial Xerus) Not vulnerable
(4.10.0-1004.4)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-gcp-5.3
Launchpad, Ubuntu, Debian
Upstream Needed

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.3.0-1009.10~18.04.1)
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 Needed

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 Needed

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Not vulnerable
(4.15.0-1030.32)
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 Needed

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.0.0-1026.27~18.04.2)
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 Needed

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Not vulnerable
(5.3.0-1011.12~18.04.1)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-hwe
Launchpad, Ubuntu, Debian
Upstream Needed

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.0.0-37.40~18.04.1)
Ubuntu 16.04 ESM (Xenial Xerus) Not vulnerable
(4.8.0-36.36~16.04.1)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-hwe-edge
Launchpad, Ubuntu, Debian
Upstream Needed

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Ignored
(was pending \[5.3.0-24.26~18.04.2\] 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-kvm
Launchpad, Ubuntu, Debian
Upstream Needed

Ubuntu 20.04 LTS (Focal Fossa) Not vulnerable
(5.4.0-1004.4)
Ubuntu 18.04 LTS (Bionic Beaver) Not vulnerable
(4.15.0-1002.2)
Ubuntu 16.04 ESM (Xenial Xerus) Not vulnerable
(4.4.0-1004.9)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-lts-trusty
Launchpad, Ubuntu, Debian
Upstream Needed

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 Needed

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-oem
Launchpad, Ubuntu, Debian
Upstream Needed

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Not vulnerable
(4.15.0-1002.3)
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-5.6
Launchpad, Ubuntu, Debian
Upstream Needed

Ubuntu 20.04 LTS (Focal Fossa) Not vulnerable
(5.4.0-1002.4)
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 Needed

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.0.0-1030.34)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-oracle
Launchpad, Ubuntu, Debian
Upstream Needed

Ubuntu 20.04 LTS (Focal Fossa) Not vulnerable
(5.4.0-1005.5)
Ubuntu 18.04 LTS (Bionic Beaver) Not vulnerable
(4.15.0-1007.9)
Ubuntu 16.04 ESM (Xenial Xerus) Not vulnerable
(4.15.0-1007.9~16.04.1)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-oracle-5.0
Launchpad, Ubuntu, Debian
Upstream Needed

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver)
Released (5.0.0-1008.13~18.04.1)
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 Needed

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Not vulnerable
(5.3.0-1011.12~18.04.1)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-raspi2
Launchpad, Ubuntu, Debian
Upstream Needed

Ubuntu 20.04 LTS (Focal Fossa) Ignored
(was needed now end-of-life)
Ubuntu 18.04 LTS (Bionic Beaver) Not vulnerable
(4.13.0-1005.5)
Ubuntu 16.04 ESM (Xenial Xerus) Not vulnerable
(4.2.0-1013.19)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-raspi2-5.3
Launchpad, Ubuntu, Debian
Upstream Needed

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Not vulnerable
(5.3.0-1017.19~18.04.1)
Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-snapdragon
Launchpad, Ubuntu, Debian
Upstream Needed

Ubuntu 20.04 LTS (Focal Fossa) Does not exist

Ubuntu 18.04 LTS (Bionic Beaver) Not vulnerable
(4.4.0-1077.82)
Ubuntu 16.04 ESM (Xenial Xerus) Not vulnerable
(4.4.0-1012.12)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist