========================================================================== Ubuntu Security Notice USN-4904-1 April 13, 2021 linux, linux-aws, linux-kvm, linux-lts-xenial, linux-raspi2, linux-snapdragon vulnerabilities ========================================================================== A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 16.04 LTS - Ubuntu 14.04 ESM Summary: Several security issues were fixed in the Linux kernel. Software Description: - linux: Linux kernel - linux-aws: Linux kernel for Amazon Web Services (AWS) systems - linux-kvm: Linux kernel for cloud environments - linux-raspi2: Linux kernel for Raspberry Pi (V8) systems - linux-snapdragon: Linux kernel for Qualcomm Snapdragon processors - linux-lts-xenial: Linux hardware enablement kernel from Xenial for Trusty Details: Ben Harris discovered that the Linux kernel would strip extended privilege attributes of files when performing a failed unprivileged system call. A local attacker could use this to cause a denial of service. (CVE-2015-1350) Andrey Konovalov discovered that the video4linux driver for Hauppauge HD PVR USB devices in the Linux kernel did not properly handle some error conditions. A physically proximate attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-16644) It was discovered that the timer stats implementation in the Linux kernel allowed the discovery of a real PID value while inside a PID namespace. A local attacker could use this to expose sensitive information. (CVE-2017-5967) Wen Xu discovered that the xfs file system implementation in the Linux kernel did not properly validate the number of extents in an inode. An attacker could use this to construct a malicious xfs image that, when mounted, could cause a denial of service (system crash). (CVE-2018-13095) It was discovered that the Fujitsu ES network device driver for the Linux kernel did not properly check for errors in some situations, leading to a NULL pointer dereference. A local attacker could use this to cause a denial of service. (CVE-2019-16231) It was discovered that the Marvell 8xxx Libertas WLAN device driver in the Linux kernel did not properly check for errors in certain situations, leading to a NULL pointer dereference. A local attacker could possibly use this to cause a denial of service. (CVE-2019-16232) It was discovered that the ADIS16400 IIO IMU Driver for the Linux kernel did not properly deallocate memory in certain error conditions. A local attacker could use this to cause a denial of service (memory exhaustion). (CVE-2019-19061) It was discovered that a race condition existed in the floppy device driver in the Linux kernel. An attacker with access to the floppy device could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-20261) Olivier Benjamin, Norbert Manthey, Martin Mazein, and Jan H. Schönherr discovered that the Xen paravirtualization bckend in the Linux kernel did not properly propagate errors to frontend drivers in some situations. An attacker in a guest VM could possibly use this to cause a denial of service (host domain crash). (CVE-2021-26930) Jan Beulich discovered that multiple Xen backends in the Linux kernel did not properly handle certain error conditions under paravirtualization. An attacker in a guest VM could possibly use this to cause a denial of service (host domain crash). (CVE-2021-26931) Jan Beulich discovered that the Xen netback backend in the Linux kernel did not properly handle certain error conditions under paravirtualization. An attacker in a guest VM could possibly use this to cause a denial of service (host domain crash). (CVE-2021-28038) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 16.04 LTS: linux-image-4.4.0-1091-kvm 4.4.0-1091.100 linux-image-4.4.0-1126-aws 4.4.0-1126.140 linux-image-4.4.0-1150-raspi2 4.4.0-1150.161 linux-image-4.4.0-1154-snapdragon 4.4.0-1154.164 linux-image-4.4.0-208-generic 4.4.0-208.240 linux-image-4.4.0-208-generic-lpae 4.4.0-208.240 linux-image-4.4.0-208-lowlatency 4.4.0-208.240 linux-image-4.4.0-208-powerpc-e500mc 4.4.0-208.240 linux-image-4.4.0-208-powerpc-smp 4.4.0-208.240 linux-image-4.4.0-208-powerpc64-emb 4.4.0-208.240 linux-image-4.4.0-208-powerpc64-smp 4.4.0-208.240 linux-image-aws 4.4.0.1126.131 linux-image-generic 4.4.0.208.214 linux-image-generic-lpae 4.4.0.208.214 linux-image-kvm 4.4.0.1091.89 linux-image-lowlatency 4.4.0.208.214 linux-image-powerpc-e500mc 4.4.0.208.214 linux-image-powerpc-smp 4.4.0.208.214 linux-image-powerpc64-emb 4.4.0.208.214 linux-image-powerpc64-smp 4.4.0.208.214 linux-image-raspi2 4.4.0.1150.150 linux-image-snapdragon 4.4.0.1154.146 linux-image-virtual 4.4.0.208.214 Ubuntu 14.04 ESM: linux-image-4.4.0-1090-aws 4.4.0-1090.94 linux-image-4.4.0-208-generic 4.4.0-208.240~14.04.1 linux-image-4.4.0-208-generic-lpae 4.4.0-208.240~14.04.1 linux-image-4.4.0-208-lowlatency 4.4.0-208.240~14.04.1 linux-image-aws 4.4.0.1090.87 linux-image-generic-lpae-lts-xenial 4.4.0.208.181 linux-image-generic-lts-xenial 4.4.0.208.181 linux-image-lowlatency-lts-xenial 4.4.0.208.181 linux-image-virtual-lts-xenial 4.4.0.208.181 After a standard system update you need to reboot your computer to make all the necessary changes. ATTENTION: Due to an unavoidable ABI change the kernel updates have been given a new version number, which requires you to recompile and reinstall all third party kernel modules you might have installed. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual, linux-powerpc), a standard system upgrade will automatically perform this as well. References: https://ubuntu.com/security/notices/USN-4904-1 CVE-2015-1350, CVE-2017-16644, CVE-2017-5967, CVE-2018-13095, CVE-2019-16231, CVE-2019-16232, CVE-2019-19061, CVE-2021-20261, CVE-2021-26930, CVE-2021-26931, CVE-2021-28038 Package Information: https://launchpad.net/ubuntu/+source/linux/4.4.0-208.240 https://launchpad.net/ubuntu/+source/linux-aws/4.4.0-1126.140 https://launchpad.net/ubuntu/+source/linux-kvm/4.4.0-1091.100 https://launchpad.net/ubuntu/+source/linux-raspi2/4.4.0-1150.161 https://launchpad.net/ubuntu/+source/linux-snapdragon/4.4.0-1154.164