========================================================================== Ubuntu Security Notice USN-3582-1 February 22, 2018 linux, linux-aws, linux-kvm, linux-raspi2, linux-snapdragon vulnerabilities ========================================================================== A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 16.04 LTS 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 2 - linux-snapdragon: Linux kernel for Snapdragon processors Details: Mohamed Ghannam discovered that the IPv4 raw socket implementation in the Linux kernel contained a race condition leading to uninitialized pointer usage. A local attacker could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2017-17712) Laurent Guerby discovered that the mbcache feature in the ext2 and ext4 filesystems in the Linux kernel improperly handled xattr block caching. A local attacker could use this to cause a denial of service. (CVE-2015-8952) Vitaly Mayatskikh discovered that the SCSI subsystem in the Linux kernel did not properly track reference counts when merging buffers. A local attacker could use this to cause a denial of service (memory exhaustion). (CVE-2017-12190) ChunYu Wang discovered that a use-after-free vulnerability existed in the SCTP protocol implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code, (CVE-2017-15115) Mohamed Ghannam discovered a use-after-free vulnerability in the DCCP protocol implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-8824) USN-3540-1 mitigated CVE-2017-5715 (Spectre Variant 2) for the amd64 architecture in Ubuntu 16.04 LTS. This update provides the compiler-based retpoline kernel mitigation for the amd64 and i386 architectures. Original advisory details: Jann Horn discovered that microprocessors utilizing speculative execution and branch prediction may allow unauthorized memory reads via sidechannel attacks. This flaw is known as Spectre. A local attacker could use this to expose sensitive information, including kernel memory. (CVE-2017-5715) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 16.04 LTS: linux-image-4.4.0-1019-kvm 4.4.0-1019.24 linux-image-4.4.0-1052-aws 4.4.0-1052.61 linux-image-4.4.0-1085-raspi2 4.4.0-1085.93 linux-image-4.4.0-1087-snapdragon 4.4.0-1087.92 linux-image-4.4.0-116-generic 4.4.0-116.140 linux-image-4.4.0-116-generic-lpae 4.4.0-116.140 linux-image-4.4.0-116-lowlatency 4.4.0-116.140 linux-image-4.4.0-116-powerpc-e500mc 4.4.0-116.140 linux-image-4.4.0-116-powerpc-smp 4.4.0-116.140 linux-image-4.4.0-116-powerpc64-emb 4.4.0-116.140 linux-image-4.4.0-116-powerpc64-smp 4.4.0-116.140 linux-image-aws 4.4.0.1052.54 linux-image-generic 4.4.0.116.122 linux-image-generic-lpae 4.4.0.116.122 linux-image-kvm 4.4.0.1019.18 linux-image-lowlatency 4.4.0.116.122 linux-image-powerpc-e500mc 4.4.0.116.122 linux-image-powerpc-smp 4.4.0.116.122 linux-image-powerpc64-emb 4.4.0.116.122 linux-image-powerpc64-smp 4.4.0.116.122 linux-image-raspi2 4.4.0.1085.85 linux-image-snapdragon 4.4.0.1087.79 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://usn.ubuntu.com/usn/usn-3582-1 CVE-2015-8952, CVE-2017-12190, CVE-2017-15115, CVE-2017-17712, CVE-2017-5715, CVE-2017-8824 Package Information: https://launchpad.net/ubuntu/+source/linux/4.4.0-116.140 https://launchpad.net/ubuntu/+source/linux-aws/4.4.0-1052.61 https://launchpad.net/ubuntu/+source/linux-kvm/4.4.0-1019.24 https://launchpad.net/ubuntu/+source/linux-raspi2/4.4.0-1085.93 https://launchpad.net/ubuntu/+source/linux-snapdragon/4.4.0-1087.92