The aufs module for the Linux kernel 3.x and 4.x does not properly maintain POSIX ACL xattr data, which allows local users to gain privileges by leveraging a group-writable setgid directory.

Affected: Ubuntu:Pro:14.04:LTS: linux-aws, Ubuntu:Pro:14.04:LTS: linux-lts-xenial, Ubuntu:Pro:16.04:LTS: linux, Ubuntu:Pro:16.04:LTS: linux-aws, Ubuntu:Pro:16.04:LTS: linux-kvm

Yiqi Sun and Kevin Wang discovered that the cgroups implementation in the Linux kernel did not properly restrict access to the cgroups v1 release_agent feature. A local attacker could use this to gain administrative privileges. (CVE-2022-0492)

It was discovered that the aufs file system in the Linux kernel did not properly restrict mount namespaces, when mounted with the non-default allow_userns option set. A local attacker could use this to gain administrative privileges. (CVE-2016-2853)

It was discovered that the aufs file system in the Linux kernel did not properly maintain POSIX ACL xattr data, when mounted with the non-default allow_userns option. A local attacker could possibly use this to gain elevated privileges. (CVE-2016-2854)

It was discovered that the f2fs file system in the Linux kernel did not properly validate metadata in some situations. An attacker could use this to construct a malicious f2fs image that, when mounted and operated on, could cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2019-19449)

It was discovered that the XFS file system implementation in the Linux kernel did not properly validate meta data in some circumstances. An attacker could use this to construct a malicious XFS image that, when mounted, could cause a denial of service. (CVE-2020-12655)

Kiyin (尹亮) discovered that the NFC LLCP protocol implementation in the Linux kernel contained a reference counting error. A local attacker could use this to cau…