Bug 1839634 (CVE-2020-10751)

Summary: CVE-2020-10751 kernel: SELinux netlink permission check bypass
Product: [Other] Security Response Reporter: Wade Mealing <wmealing>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: acaringi, airlied, bhu, blc, bmasney, brdeoliv, bskeggs, dhoward, dvlasenk, esammons, fhrbata, hdegoede, hkrzesin, iboverma, ichavero, itamar, jarodwilson, jeremy, jforbes, jglisse, jlelli, john.j5live, jonathan, josef, jross, jshortt, jstancek, jwboyer, kcarcia, kernel-maint, kernel-mgr, lgoncalv, linville, masami256, matt, mchehab, mcressma, mjg59, mlangsdo, nmurray, omosnace, psampaio, ptalbert, qzhao, rt-maint, rvrbovsk, steved, williams
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in the Linux kernel’s SELinux LSM hook implementation, where it anticipated the skb would only contain a single Netlink message. The hook incorrectly validated the first Netlink message in the skb only, to allow or deny the rest of the messages within the skb with the granted permissions and without further processing. At this time, there is no known ability for an attacker to abuse this flaw.
Story Points: ---
Clone Of: Environment:
Last Closed: 2020-09-29 22:01:23 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 1839643, 1839644, 1839645, 1839650, 1844353, 1845039    
Bug Blocks: 1830297    

Description Wade Mealing 2020-05-25 06:43:06 UTC
A flaw was found in the Linux kernel SELinux LSM hook implementation before version 5.7, where it incorrectly assumed that an skb would only contain a single netlink message.  The hook would incorrectly only validate the first netlink message in the skb and allow or deny the rest of the messages within the skb with the granted permission without further processing.

At this time, there is no known ability for an attacker to use this to abuse this flaw as capabilities are required to process any 'modify' operation.

Comment 11 Wade Mealing 2020-06-05 07:55:20 UTC
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1844353]

Comment 13 Petr Matousek 2020-06-08 10:50:29 UTC
Mitigation:

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Comment 15 Justin M. Forbes 2020-06-08 12:35:04 UTC
This was fixed for Fedora with the 5.6.11 stable kernel updates.

Comment 16 errata-xmlrpc 2020-09-29 19:00:01 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2020:4062 https://access.redhat.com/errata/RHSA-2020:4062

Comment 17 errata-xmlrpc 2020-09-29 20:54:21 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2020:4060 https://access.redhat.com/errata/RHSA-2020:4060

Comment 18 Product Security DevOps Team 2020-09-29 22:01:23 UTC
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2020-10751

Comment 19 errata-xmlrpc 2020-11-04 00:51:09 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:4431 https://access.redhat.com/errata/RHSA-2020:4431

Comment 20 errata-xmlrpc 2020-11-04 02:23:37 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:4609 https://access.redhat.com/errata/RHSA-2020:4609