Bug 1707796 (CVE-2018-20836)

Summary: CVE-2018-20836 kernel: race condition in smp_task_timedout() and smp_task_done() in drivers/scsi/libsas/sas_expander.c leads to use-after-free
Product: [Other] Security Response Reporter: msiddiqu
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: acaringi, anrussel, apmukher, asavkov, bhu, blc, brdeoliv, dhoward, dvlasenk, dvolkov, esammons, fhrbata, gsuckevi, hkrzesin, iboverma, jkacur, joe.lawrence, jpoimboe, jross, jstancek, jthierry, kernel-mgr, lgoncalv, lilu, matt, mcressma, mlangsdo, mmilgram, nmurray, rhandlin, rt-maint, rvrbovsk, sbalasub, williams, wmealing, ycote, ykopkova
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 implementation of the SAS expander subsystem, where a race condition exists in the smp_task_timedout() and smp_task_done() in drivers/scsi/libsas/sas_expander.c. An attacker could abuse this flaw to corrupt memory and escalate privileges.
Story Points: ---
Clone Of: Environment:
Last Closed: 2020-09-29 21:57:50 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On: 1796288, 1796289, 1796290, 1796291, 1796292, 1796293, 1796294, 1796295, 1796296, 1796297, 1796298, 1796299, 1796300, 1796301, 1796302, 1796304, 1796305, 1796311, 1796316, 1796700, 1796701, 1796702, 1796703, 1796704, 1798260, 1798261, 1798262, 1798263, 1798264, 1798265, 1888694, 1895462, 1895463    
Bug Blocks: 1707797    

Description msiddiqu 2019-05-08 11:43:43 UTC
An issue was discovered in the Linux kernels implementation of SAS expander functionality. A race condition in smp_task_timedout() and smp_task_done() in drivers/scsi/libsas/sas_expander.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

Comment 18 errata-xmlrpc 2020-09-29 18:57:36 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 19 errata-xmlrpc 2020-09-29 20:51:06 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 20 Product Security DevOps Team 2020-09-29 21:57:50 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-2018-20836

Comment 38 errata-xmlrpc 2020-12-22 09:31:34 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.6 Extended Update Support

Via RHSA-2020:5656 https://access.redhat.com/errata/RHSA-2020:5656

Comment 40 errata-xmlrpc 2021-01-05 10:20:27 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.7 Extended Update Support

Via RHSA-2021:0019 https://access.redhat.com/errata/RHSA-2021:0019