CVE-2017-2636

Publication date 7 March 2017

Last updated 25 August 2025

Ubuntu priority

High

Why this priority?

Cvss 3 Severity Score

7.0 · High

Score breakdown

Description

Race condition in drivers/tty/n_hdlc.c in the Linux kernel through 4.10.1 allows local users to gain privileges or cause a denial of service (double free) by setting the HDLC line discipline.

From the Ubuntu Security Team

Alexander Popov discovered that the N_HDLC line discipline implementation in the Linux kernel contained a double-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly gain administrative privileges.

Read the notes from the security team

Status

Package Ubuntu Release Status
linux 17.10 artful
Not affected
17.04 zesty
Not affected
16.10 yakkety
Fixed 4.8.0-41.44
16.04 LTS xenial
Fixed 4.4.0-66.87
14.04 LTS trusty
Fixed 3.13.0-112.159
12.04 LTS precise
Fixed 3.2.0-124.167
linux-armadaxp 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
12.04 LTS precise
Fixed 3.2.0-1685.112
linux-aws 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial
Fixed 4.4.0-1007.16
14.04 LTS trusty
Not affected
12.04 LTS precise Not in release
linux-azure 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety 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 in release
14.04 LTS trusty Not in release
linux-flo 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Ignored end of life
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-gcp 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety 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
16.10 yakkety Not in release
16.04 LTS xenial
Fixed 4.4.0-1005.6
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-goldfish 17.10 artful Not in release
17.04 zesty Ignored end of life
16.10 yakkety Ignored end of life
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-grouper 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-hwe 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial
Fixed 4.8.0-41.44~16.04.1
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-hwe-edge 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial
Fixed 4.8.0-41.44~16.04.1
14.04 LTS trusty Not in release
12.04 LTS precise 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
16.10 yakkety Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Ignored end of life
linux-linaro-shared 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Ignored end of life
linux-linaro-vexpress 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Ignored end of life
linux-lts-quantal 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Ignored end of life
linux-lts-raring 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Ignored end of life
linux-lts-saucy 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Ignored end of life
linux-lts-trusty 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
12.04 LTS precise
Fixed 3.13.0-112.159~precise1
linux-lts-utopic 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-lts-vivid 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-lts-wily 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-lts-xenial 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty
Fixed 4.4.0-66.87~14.04.1
12.04 LTS precise Not in release
linux-maguro 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-mako 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Ignored end of life
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-manta 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
12.04 LTS precise 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
16.10 yakkety Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Ignored end of life
linux-raspi2 17.10 artful
Not affected
17.04 zesty
Not affected
16.10 yakkety
Fixed 4.8.0-1028.31
16.04 LTS xenial
Fixed 4.4.0-1046.53
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-snapdragon 17.10 artful
Not affected
17.04 zesty
Not affected
16.10 yakkety
Fixed 4.4.0-1050.54
16.04 LTS xenial
Fixed 4.4.0-1050.54
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-ti-omap4 17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
12.04 LTS precise
Fixed 3.2.0-1502.129

Notes

jdstrand

android kernels (flo, goldfish, grouper, maguro, mako and manta) are not supported on the Ubuntu Touch 14.10 and earlier preview kernels linux-lts-saucy no longer receives official support linux-lts-quantal no longer receives official support

tyhicks

all of our kernels are affected as CONFIG_N_HDLC=m is set in all releases

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 7.0 · High
Attack vector Local
Attack complexity High
Privileges required Low
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact High
Availability impact High
Vector CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

References

Related Ubuntu Security Notices (USN)

    • USN-3220-2
    • Linux kernel (Xenial HWE) vulnerability
    • 8 March 2017
    • USN-3220-1
    • Linux kernel vulnerability
    • 8 March 2017
    • USN-3220-3
    • Linux kernel (AWS) vulnerability
    • 9 March 2017
    • USN-3221-2
    • Linux kernel (HWE) vulnerability
    • 8 March 2017
    • USN-3219-1
    • Linux kernel vulnerability
    • 7 March 2017
    • USN-3219-2
    • Linux kernel (Trusty HWE) vulnerability
    • 8 March 2017
    • USN-3218-1
    • Linux kernel vulnerability
    • 7 March 2017
    • USN-3221-1
    • Linux kernel vulnerability
    • 8 March 2017

Other references