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CVE-2017-1000255

Publication date 9 October 2017

Last updated 24 July 2024

Ubuntu priority

High

Why this priority?

Cvss 3 Severity Score

5.5 · Medium

Score breakdown

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.

From the Ubuntu Security Team

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.

Read the notes from the security team

Status

Package Ubuntu Release Status
linux 17.10 artful
Fixed 4.13.0-17.20
17.04 zesty
Fixed 4.10.0-37.41
16.04 LTS xenial
Not affected
14.04 LTS trusty
Not affected
linux-armadaxp 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-aws 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial
Not affected
14.04 LTS trusty
Not affected
linux-azure 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial
Not affected
14.04 LTS trusty
Not affected
linux-euclid 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial
Not affected
14.04 LTS trusty Not in release
linux-flo 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Ignored
14.04 LTS trusty Not in release
linux-gcp 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial
Not affected
14.04 LTS trusty Not in release
linux-gke 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial
Not affected
14.04 LTS trusty Not in release
linux-goldfish 17.10 artful Not in release
17.04 zesty
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty Not in release
linux-grouper 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-hwe 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial
Fixed 4.10.0-37.41~16.04.1
14.04 LTS trusty Not in release
linux-hwe-edge 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial
Fixed 4.10.0-37.41~16.04.1
14.04 LTS trusty Not in release
linux-kvm 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial
Not affected
14.04 LTS trusty Not in release
linux-linaro-omap 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-linaro-shared 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-linaro-vexpress 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-lts-quantal 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-lts-raring 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-lts-saucy 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-lts-trusty 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-lts-utopic 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-lts-vivid 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-lts-wily 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-lts-xenial 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty
Not affected
linux-maguro 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-mako 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Ignored
14.04 LTS trusty Not in release
linux-manta 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-oem 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial
Not affected
14.04 LTS trusty Not in release
linux-qcm-msm 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-raspi2 17.10 artful
Not affected
17.04 zesty
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty Not in release
linux-snapdragon 17.10 artful
Not affected
17.04 zesty
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty Not in release
linux-ti-omap4 17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release

Notes

sbeattie

introduced in v4.9 cycle, PPC on power8 only

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
linux

Severity score breakdown

Parameter Value
Base score 5.5 · Medium
Attack vector Local
Attack complexity Low
Privileges required Low
User interaction None
Scope Unchanged
Confidentiality None
Integrity impact High
Availability impact None
Vector CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

References

Related Ubuntu Security Notices (USN)

    • USN-3487-1
    • Linux kernel vulnerabilities
    • 21 November 2017
    • USN-3443-2
    • Linux kernel (HWE) vulnerabilities
    • 10 October 2017
    • USN-3443-1
    • Linux kernel vulnerabilities
    • 10 October 2017

Other references