Bug 1903244 (CVE-2020-29368) - CVE-2020-29368 kernel: the copy-on-write implementation can grant unintended write access because of a race condition in a THP mapcount check
Summary: CVE-2020-29368 kernel: the copy-on-write implementation can grant unintended ...
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2020-29368
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1981692 2089089 2089412 2089413 1903245 1974659 1974660
Blocks: 1903246
TreeView+ depends on / blocked
 
Reported: 2020-12-01 17:09 UTC by Guilherme de Almeida Suckevicz
Modified: 2022-05-26 11:51 UTC (History)
39 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
An issue was discovered in __split_huge_pmd in mm/huge_memory.c in the Linux kernel. The copy-on-write implementation can grant unintended write access because of a race condition in a THP mapcount check.
Clone Of:
Environment:
Last Closed: 2021-11-09 19:52:50 UTC


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2021:4140 0 None None None 2021-11-09 17:21:16 UTC
Red Hat Product Errata RHSA-2021:4356 0 None None None 2021-11-09 18:22:56 UTC

Description Guilherme de Almeida Suckevicz 2020-12-01 17:09:20 UTC
An issue was discovered in __split_huge_pmd in mm/huge_memory.c in the Linux kernel before 5.7.5. The copy-on-write implementation can grant unintended write access because of a race condition in a THP mapcount check.

Reference:
https://bugs.chromium.org/p/project-zero/issues/detail?id=2045

Upstream patch:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c444eb564fb16645c172d550359cb3d75fe8a040

Comment 1 Guilherme de Almeida Suckevicz 2020-12-01 17:09:52 UTC
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1903245]

Comment 2 Justin M. Forbes 2020-12-02 14:15:03 UTC
This was fixed for Fedora with the 5.7.5 stable kernel updates.

Comment 17 errata-xmlrpc 2021-11-09 17:21:13 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:4140 https://access.redhat.com/errata/RHSA-2021:4140

Comment 18 errata-xmlrpc 2021-11-09 18:22:54 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:4356 https://access.redhat.com/errata/RHSA-2021:4356

Comment 19 Product Security DevOps Team 2021-11-09 19:52:45 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-2020-29368


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