CVE-2018-20836: Race Condition

Published Sep 25, 2018
·
Updated

A flaw was found in the Linux kernel’s implementation of the SAS expander subsystem, where a race condition exists in the smptasktimedout() and smptaskdone() in drivers/scsi/libsas/sasexpander.c. An attacker could abuse this flaw to corrupt memory and escalate privileges.

Other sources

An issue was discovered in the Linux kernel before 4.20. There is a race condition in smptasktimedout() and smptaskdone() in drivers/scsi/libsas/sasexpander.c, leading to a use-after-free.

An issue was discovered in the Linux kernels implementation of SAS expander functionality. A race condition in smptasktimedout() and smptaskdone() in drivers/scsi/libsas/sasexpander.c could allow an attacker who is able to issue SAS commands to create a conditon where it could be manipulated into a use-after-free scenario allowing for memory corruption or possibly escalate privileges.

Upstream patch:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b90cd6f2b905905fb42671009dc0e27c310a16ae https://github.com/torvalds/linux/commit/b90cd6f2b905905fb42671009dc0e27c310a16ae

Red Hat

Affected Software

27 affected componentsFixes available
redhat/kernel-rt<0:3.10.0-1160.rt56.1131.el7
0:3.10.0-1160.rt56.1131.el7
redhat/kernel<0:3.10.0-1160.el7
0:3.10.0-1160.el7
redhat/kernel<0:3.10.0-957.65.1.el7
0:3.10.0-957.65.1.el7
redhat/kernel<0:3.10.0-1062.43.1.el7
0:3.10.0-1062.43.1.el7
Linux Linux kernel<3.16.72
Linux Linux kernel>=3.17<3.18.140
Linux Linux kernel>=3.19<4.4.180
Linux Linux kernel>=4.5<4.9.175
Linux Linux kernel>=4.10<4.14.118
Linux Linux kernel>=4.15<4.19.42
Canonical Ubuntu Linux=16.04
Debian Debian Linux=8.0
Debian Debian Linux=9.0
Debian Debian Linux=10.0
F5 Traffix Signaling Delivery Controller=5.0.0
F5 Traffix Signaling Delivery Controller=5.1.0
NetApp Active Iq Unified Manager Vmware Vsphere>=9.5
NetApp Snapprotect
NetApp Solidfire \& Hci Management Node
NetApp Solidfire \& Hci Storage Node
NetApp Storage Replication Adapter For Clustered Data Ontap Vmware Vsphere
NetApp Vasa Provider For Clustered Data Ontap>=7.2
NetApp Virtual Storage Console Vmware Vsphere>=7.2
NetApp Hci Compute Node
openSUSE Leap=15.0
openSUSE Leap=15.1
debian/linux
5.10.223-15.10.262-16.1.176-16.1.180-16.12.94-16.12.101-17.1.7-17.1.8-1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade redhat/kernel-rt to a version that resolves this vulnerability.

    Fixed in 0:3.10.0-1160.rt56.1131.el7
  2. Upgrade

    Upgrade redhat/kernel to a version that resolves this vulnerability.

    Fixed in 0:3.10.0-1160.el7
  3. Upgrade

    Upgrade redhat/kernel to a version that resolves this vulnerability.

    Fixed in 0:3.10.0-957.65.1.el7
  4. Upgrade

    Upgrade redhat/kernel to a version that resolves this vulnerability.

    Fixed in 0:3.10.0-1062.43.1.el7
  5. Upgrade

    Upgrade debian/linux to a version that resolves this vulnerability.

    Fixed in 5.10.223-1Fixed in 5.10.262-1Fixed in 6.1.176-1Fixed in 6.1.180-1Fixed in 6.12.94-1Fixed in 6.12.101-1Fixed in 7.1.7-1Fixed in 7.1.8-1
  6. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Patch b90cd6f2b905905fb42671009dc0e27c310a16ae

Event History

Sep 25, 2018
CVE Published
12:00 AM
May 7, 2019
CVE Published
via MITRE·01:04 PM
Data Sourced
via MITRE·01:04 PM
Description
Data Sourced
via NVD·02:29 PM
RemedyDescriptionSeverityWeaknessAffected Software
May 8, 2019
Data Sourced
via Red Hat·11:43 AM
DescriptionSeverityAffected Software
Jan 11, 2024
Data Sourced
via Launchpad·11:00 PM
Description
Jul 8, 2026
Data Sourced
via Ubuntu·10:15 AM
RemedyDescriptionSeverityAffected Software
Aug 12, 2026
Data Sourced
via Debian·11:23 AM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the severity of CVE-2018-20836?

CVE-2018-20836 is classified as a high severity vulnerability due to its potential for privilege escalation and memory corruption.

2

How do I fix CVE-2018-20836?

To fix CVE-2018-20836, users should update to the latest kernel version that addresses this vulnerability according to their distribution.

3

Which systems are affected by CVE-2018-20836?

CVE-2018-20836 affects various versions of the Linux kernel up to version 4.19.42 as well as specific Red Hat kernel packages.

4

What types of attacks can exploit CVE-2018-20836?

An attacker can exploit CVE-2018-20836 to potentially cause memory corruption and escalate privileges on the affected systems.

5

Which distributions provide patches for CVE-2018-20836?

Patches for CVE-2018-20836 are available from major distributions such as Red Hat, Debian, and Ubuntu.

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