N/A - USN-4017-1

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 19.04 - Ubuntu 18.10 - Ubuntu 18.04 LTS - Ubuntu 16.04 LTS

Summary:

The system could be made to crash if it received specially crafted network traffic.

Software Description: - linux: Linux kernel - linux-aws: Linux kernel for Amazon Web Services (AWS) systems - linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems - linux-kvm: Linux kernel for cloud environments - linux-raspi2: Linux kernel for Raspberry Pi 2 - linux-snapdragon: Linux kernel for Snapdragon processors - linux-azure: Linux kernel for Microsoft Azure Cloud systems - linux-hwe: Linux hardware enablement (HWE) kernel - linux-oem: Linux kernel for OEM processors - linux-oracle: Linux kernel for Oracle Cloud systems - linux-aws-hwe: Linux kernel for Amazon Web Services (AWS-HWE) systems

Details:

Jonathan Looney discovered that the TCP retransmission queue implementation in the Linux kernel could be fragmented when handling certain TCP Selective Acknowledgment (SACK) sequences. A remote attacker could use this to cause a denial of service. (CVE-2019-11478)

Jonathan Looney discovered that an integer overflow existed in the Linux kernel when handling TCP Selective Acknowledgments (SACKs). A remote attacker could use this to cause a denial of service (system crash). (CVE-2019-11477)

Update instructions:

The problem can be corrected by updating your system to the following package versions:

Ubuntu 19.04:
linux-image-5.0.0-1008-aws 5.0.0-1008.8
linux-image-5.0.0-1008-gcp 5.0.0-1008.8
linux-image-5.0.0-1008-kvm 5.0.0-1008.8
linux-image-5.0.0-1010-raspi2 5.0.0-1010.10
linux-image-5.0.0-1014-snapdragon 5.0.0-1014.14
linux-image-5.0.0-17-generic 5.0.0-17.18
linux-image-5.0.0-17-generic-lpae 5.0.0-17.18
linux-image-5.0.0-17-lowlatency 5.0.0-17.18
linux-image-aws 5.0.0.1008.8
linux-image-gcp 5.0.0.1008.8
linux-image-generic 5.0.0.17.18
linux-image-generic-lpae 5.0.0.17.18
linux-image-gke 5.0.0.1008.8
linux-image-kvm 5.0.0.1008.8
linux-image-lowlatency 5.0.0.17.18
linux-image-raspi2 5.0.0.1010.7
linux-image-snapdragon 5.0.0.1014.7
linux-image-virtual 5.0.0.17.18

Ubuntu 18.10:
linux-image-4.18.0-1013-gcp 4.18.0-1013.14
linux-image-4.18.0-1014-kvm 4.18.0-1014.14
linux-image-4.18.0-1016-raspi2 4.18.0-1016.18
linux-image-4.18.0-1018-aws 4.18.0-1018.20
linux-image-4.18.0-1020-azure 4.18.0-1020.20
linux-image-4.18.0-22-generic 4.18.0-22.23
linux-image-4.18.0-22-generic-lpae 4.18.0-22.23
linux-image-4.18.0-22-lowlatency 4.18.0-22.23
linux-image-4.18.0-22-snapdragon 4.18.0-22.23
linux-image-aws 4.18.0.1018.18
linux-image-azure 4.18.0.1020.21
linux-image-gcp 4.18.0.1013.13
linux-image-generic 4.18.0.22.23
linux-image-generic-lpae 4.18.0.22.23
linux-image-gke 4.18.0.1013.13
linux-image-kvm 4.18.0.1014.14
linux-image-lowlatency 4.18.0.22.23
linux-image-raspi2 4.18.0.1016.13
linux-image-snapdragon 4.18.0.22.23
linux-image-virtual 4.18.0.22.23

Ubuntu 18.04 LTS:
linux-image-4.15.0-1015-oracle 4.15.0-1015.17
linux-image-4.15.0-1034-gcp 4.15.0-1034.36
linux-image-4.15.0-1036-kvm 4.15.0-1036.36
linux-image-4.15.0-1038-raspi2 4.15.0-1038.40
linux-image-4.15.0-1041-aws 4.15.0-1041.43
linux-image-4.15.0-1043-oem 4.15.0-1043.48
linux-image-4.15.0-1055-snapdragon 4.15.0-1055.59
linux-image-4.15.0-52-generic 4.15.0-52.56
linux-image-4.15.0-52-generic-lpae 4.15.0-52.56
linux-image-4.15.0-52-lowlatency 4.15.0-52.56
linux-image-4.18.0-1020-azure 4.18.0-1020.20~18.04.1
linux-image-4.18.0-22-generic 4.18.0-22.23~18.04.1
linux-image-4.18.0-22-generic-lpae 4.18.0-22.23~18.04.1
linux-image-4.18.0-22-lowlatency 4.18.0-22.23~18.04.1
linux-image-4.18.0-22-snapdragon 4.18.0-22.23~18.04.1
linux-image-aws 4.15.0.1041.40
linux-image-azure 4.18.0.1020.19
linux-image-gcp 4.15.0.1034.36
linux-image-generic 4.15.0.52.54
linux-image-generic-hwe-18.04 4.18.0.22.72
linux-image-generic-lpae 4.15.0.52.54
linux-image-generic-lpae-hwe-18.04 4.18.0.22.72
linux-image-kvm 4.15.0.1036.36
linux-image-lowlatency 4.15.0.52.54
linux-image-lowlatency-hwe-18.04 4.18.0.22.72
linux-image-oem 4.15.0.1043.47
linux-image-oracle 4.15.0.1015.18
linux-image-raspi2 4.15.0.1038.36
linux-image-snapdragon 4.15.0.1055.58
linux-image-snapdragon-hwe-18.04 4.18.0.22.72
linux-image-virtual 4.15.0.52.54
linux-image-virtual-hwe-18.04 4.18.0.22.72

Ubuntu 16.04 LTS:
linux-image-4.15.0-1015-oracle 4.15.0-1015.17~16.04.1
linux-image-4.15.0-1034-gcp 4.15.0-1034.36~16.04.1
linux-image-4.15.0-1041-aws 4.15.0-1041.43~16.04.1
linux-image-4.15.0-1047-azure 4.15.0-1047.51
linux-image-4.15.0-52-generic 4.15.0-52.56~16.04.1
linux-image-4.15.0-52-generic-lpae 4.15.0-52.56~16.04.1
linux-image-4.15.0-52-lowlatency 4.15.0-52.56~16.04.1
linux-image-4.4.0-1048-kvm 4.4.0-1048.55
linux-image-4.4.0-1085-aws 4.4.0-1085.96
linux-image-4.4.0-1111-raspi2 4.4.0-1111.120
linux-image-4.4.0-1115-snapdragon 4.4.0-1115.121
linux-image-4.4.0-151-generic 4.4.0-151.178
linux-image-4.4.0-151-generic-lpae 4.4.0-151.178
linux-image-4.4.0-151-lowlatency 4.4.0-151.178
linux-image-4.4.0-151-powerpc-e500mc 4.4.0-151.178
linux-image-4.4.0-151-powerpc-smp 4.4.0-151.178
linux-image-4.4.0-151-powerpc64-emb 4.4.0-151.178
linux-image-4.4.0-151-powerpc64-smp 4.4.0-151.178
linux-image-aws 4.4.0.1085.88
linux-image-aws-hwe 4.15.0.1041.41
linux-image-azure 4.15.0.1047.51
linux-image-gcp 4.15.0.1034.48
linux-image-generic 4.4.0.151.159
linux-image-generic-hwe-16.04 4.15.0.52.73
linux-image-generic-lpae 4.4.0.151.159
linux-image-generic-lpae-hwe-16.04 4.15.0.52.73
linux-image-gke 4.15.0.1034.48
linux-image-kvm 4.4.0.1048.48
linux-image-lowlatency 4.4.0.151.159
linux-image-lowlatency-hwe-16.04 4.15.0.52.73
linux-image-oem 4.15.0.52.73
linux-image-oracle 4.15.0.1015.9
linux-image-powerpc-e500mc 4.4.0.151.159
linux-image-powerpc-smp 4.4.0.151.159
linux-image-powerpc64-emb 4.4.0.151.159
linux-image-powerpc64-smp 4.4.0.151.159
linux-image-raspi2 4.4.0.1111.111
linux-image-snapdragon 4.4.0.1115.107
linux-image-virtual 4.4.0.151.159
linux-image-virtual-hwe-16.04 4.15.0.52.73

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/4017-1
CVE-2019-11477, CVE-2019-11478,
https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/SACKPanic

Package Information:
https://launchpad.net/ubuntu/+source/linux/5.0.0-17.18
https://launchpad.net/ubuntu/+source/linux-aws/5.0.0-1008.8
https://launchpad.net/ubuntu/+source/linux-gcp/5.0.0-1008.8
https://launchpad.net/ubuntu/+source/linux-kvm/5.0.0-1008.8
https://launchpad.net/ubuntu/+source/linux-raspi2/5.0.0-1010.10
https://launchpad.net/ubuntu/+source/linux-snapdragon/5.0.0-1014.14
https://launchpad.net/ubuntu/+source/linux/4.18.0-22.23
https://launchpad.net/ubuntu/+source/linux-aws/4.18.0-1018.20
https://launchpad.net/ubuntu/+source/linux-azure/4.18.0-1020.20
https://launchpad.net/ubuntu/+source/linux-gcp/4.18.0-1013.14
https://launchpad.net/ubuntu/+source/linux-kvm/4.18.0-1014.14
https://launchpad.net/ubuntu/+source/linux-raspi2/4.18.0-1016.18
https://launchpad.net/ubuntu/+source/linux/4.15.0-52.56
https://launchpad.net/ubuntu/+source/linux-aws/4.15.0-1041.43
https://launchpad.net/ubuntu/+source/linux-azure/4.18.0-1020.20~18.04.1
https://launchpad.net/ubuntu/+source/linux-gcp/4.15.0-1034.36
https://launchpad.net/ubuntu/+source/linux-hwe/4.18.0-22.23~18.04.1
https://launchpad.net/ubuntu/+source/linux-kvm/4.15.0-1036.36
https://launchpad.net/ubuntu/+source/linux-oem/4.15.0-1043.48
https://launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1015.17
https://launchpad.net/ubuntu/+source/linux-raspi2/4.15.0-1038.40
https://launchpad.net/ubuntu/+source/linux-snapdragon/4.15.0-1055.59
https://launchpad.net/ubuntu/+source/linux/4.4.0-151.178
https://launchpad.net/ubuntu/+source/linux-aws/4.4.0-1085.96
https://launchpad.net/ubuntu/+source/linux-aws-hwe/4.15.0-1041.43~16.04.1
https://launchpad.net/ubuntu/+source/linux-azure/4.15.0-1047.51
https://launchpad.net/ubuntu/+source/linux-gcp/4.15.0-1034.36~16.04.1
https://launchpad.net/ubuntu/+source/linux-hwe/4.15.0-52.56~16.04.1
https://launchpad.net/ubuntu/+source/linux-kvm/4.4.0-1048.55
https://launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1015.17~16.04.1
https://launchpad.net/ubuntu/+source/linux-raspi2/4.4.0-1111.120
https://launchpad.net/ubuntu/+source/linux-snapdragon/4.4.0-1115.121