| Revision Date: | 2017-10-30 | Version: | 1 | | Title: | CVE-2017-1000255 on Ubuntu 16.04 LTS (xenial) - high. | | Description: | On Linux running on PowerPC hardware (Power8 or later) a user process can craft a signal frame and then do a sigreturn so that the kernel will take an exception (interrupt), and use the r1 value *from the signal frame* as the kernel stack pointer. As part of the exception entry the content of the signal frame is written to the kernel stack, allowing an attacker to overwrite arbitrary locations with arbitrary values. The exception handling does produce an oops, and a panic if panic_on_oops=1, but only after kernel memory has been over written. This flaw was introduced in commit: "5d176f751ee3 (powerpc: tm: Enable transactional memory (TM) lazily for userspace)" which was merged upstream into v4.9-rc1. Please note that kernels built with CONFIG_PPC_TRANSACTIONAL_MEM=n are not vulnerable. It was discovered that on the PowerPC architecture, the kernel did not properly sanitize the signal stack when handling sigreturn(). A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code.
| | Family: | unix | Class: | vulnerability | | Status: | | Reference(s): | CVE-2017-1000255
| | Platform(s): | Ubuntu 16.04 LTS
| Product(s): | | | Definition Synopsis | | Ubuntu 16.04 LTS (xenial) is installed. AND Package Information
NOT While related to the CVE in some way, the 'linux' package in xenial is not affected.
OR NOT While related to the CVE in some way, the 'linux-aws' package in xenial is not affected.
OR NOT While related to the CVE in some way, the 'linux-azure' package in xenial is not affected (note: 'ppc only').
OR NOT While related to the CVE in some way, the 'linux-euclid' package in xenial is not affected.
OR While related to the CVE in some way, a decision has been made to ignore it (note: 'abandoned').
OR NOT While related to the CVE in some way, the 'linux-gcp' package in xenial is not affected (note: 'ppc only').
OR NOT While related to the CVE in some way, the 'linux-gke' package in xenial is not affected.
OR NOT While related to the CVE in some way, the 'linux-goldfish' package in xenial is not affected.
OR The 'linux-hwe' package in xenial was vulnerable but has been fixed (note: '4.10.0-37.41~16.04.1').
OR The 'linux-hwe-edge' package in xenial was vulnerable but has been fixed (note: '4.10.0-37.41~16.04.1').
OR NOT While related to the CVE in some way, the 'linux-kvm' package in xenial is not affected.
OR While related to the CVE in some way, a decision has been made to ignore it (note: 'abandoned').
OR NOT While related to the CVE in some way, the 'linux-oem' package in xenial is not affected (note: '4.13.0-1008.9').
OR NOT While related to the CVE in some way, the 'linux-raspi2' package in xenial is not affected (note: 'ppc only').
OR NOT While related to the CVE in some way, the 'linux-snapdragon' package in xenial is not affected (note: 'ppc only').
|
|