Bug 2031930 (CVE-2021-0920)

Summary:	CVE-2021-0920 kernel: Use After Free in unix_gc() which could result in a local privilege escalation
Product:	[Other] Security Response	Reporter:	Michael Kaplan <mkaplan>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	acaringi, adscvr, airlied, alciregi, asavkov, bdettelb, bhu, brdeoliv, bskeggs, chwhite, crwood, ctoe, dhoward, dvlasenk, fhrbata, fpacheco, hdegoede, hkrzesin, jarod, jarodwilson, jburrell, jeremy, jfaracco, jforbes, jglisse, jlelli, joe.lawrence, jonathan, josef, jpoimboe, jshortt, jstancek, jthierry, jwboyer, kcarcia, kernel-maint, kernel-mgr, kpatch-maint, lgoncalv, linville, lzampier, masami256, mchehab, michal.skrivanek, mperina, nmurray, nobody, ptalbert, qzhao, rhandlin, rvrbovsk, sbonazzo, scweaver, steved, vkumar, walters, williams, ycote
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel 5.14 rc4	Doc Type:	If docs needed, set a value
Doc Text:	A vulnerability was found in unix_dgram_recvmsg in net/unix/af_unix.c in the Linux kernel's garbage collection for Unix domain socket file handlers. In this flaw, a missing cleanup may lead to a use-after-free due to a race problem. This flaw allows a local user to crash the system or escalate their privileges on the system. A read-after-free memory flaw was found in the Linux kernel's garbage collection for Unix domain socket file handlers in the way users call close() and fget() simultaneously and can potentially trigger a race condition. This flaw allows a local user to crash the system or escalate their privileges on the system.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2022-05-11 13:15:31 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:	2031966, 2031967, 2031968, 2031969, 2031970, 2031971, 2031972, 2031973, 2031974, 2031975, 2031976, 2031977, 2031978, 2031979, 2031980, 2031981, 2031982, 2031983, 2031984, 2031985, 2031986, 2031987, 2031988, 2031989, 2031990, 2031991, 2031992, 2032818, 2032819, 2047640
Bug Blocks:	2030656

Description Michael Kaplan 2021-12-13 18:03:02 UTC

A flaw was found in the linux kernel, unix_gc() assumes that candidate sockets can never gain an external reference (i.e.  be installed into an fd) while the unix_gc_lock is held.  Except for MSG_PEEK this is guaranteed by modifying inflight count under the unix_gc_lock.

References:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cbcf01128d0a92e131bd09f1688fe032480b65ca

Comment 9 Sandro Bonazzola 2022-01-25 10:20:39 UTC

Isn't this affecting Fedora too?

Comment 10 Sandro Bonazzola 2022-01-28 08:01:19 UTC

Created oVirt tracking bug for this issue:

Affects: oVirt Node 4.4 [ bug 2047640 ]

Comment 11 errata-xmlrpc 2022-02-22 09:00:50 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.2 Extended Update Support

Via RHSA-2022:0590 https://access.redhat.com/errata/RHSA-2022:0590

Comment 12 errata-xmlrpc 2022-02-22 09:12:16 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2022:0592 https://access.redhat.com/errata/RHSA-2022:0592

Comment 13 errata-xmlrpc 2022-02-22 15:15:34 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.2 Extended Update Support

Via RHSA-2022:0629 https://access.redhat.com/errata/RHSA-2022:0629

Comment 14 errata-xmlrpc 2022-02-22 15:54:40 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.2 Extended Update Support

Via RHSA-2022:0636 https://access.redhat.com/errata/RHSA-2022:0636

Comment 15 errata-xmlrpc 2022-02-22 16:58:04 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2022:0620 https://access.redhat.com/errata/RHSA-2022:0620

Comment 16 errata-xmlrpc 2022-02-22 17:00:48 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2022:0622 https://access.redhat.com/errata/RHSA-2022:0622

Comment 17 errata-xmlrpc 2022-03-08 15:02:56 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.4 Extended Update Support

Via RHSA-2022:0771 https://access.redhat.com/errata/RHSA-2022:0771

Comment 18 errata-xmlrpc 2022-03-08 15:54:15 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.4 Extended Update Support

Via RHSA-2022:0772 https://access.redhat.com/errata/RHSA-2022:0772

Comment 19 errata-xmlrpc 2022-03-08 17:51:15 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.4 Extended Update Support

Via RHSA-2022:0777 https://access.redhat.com/errata/RHSA-2022:0777

Comment 20 errata-xmlrpc 2022-03-10 15:04:07 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2022:0819 https://access.redhat.com/errata/RHSA-2022:0819

Comment 21 errata-xmlrpc 2022-03-10 15:31:42 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.1 Update Services for SAP Solutions

Via RHSA-2022:0823 https://access.redhat.com/errata/RHSA-2022:0823

Comment 22 errata-xmlrpc 2022-03-10 16:15:20 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2022:0825 https://access.redhat.com/errata/RHSA-2022:0825

Comment 23 errata-xmlrpc 2022-03-14 09:22:48 UTC

This issue has been addressed in the following products:

  Red Hat Virtualization 4 for Red Hat Enterprise Linux 8

Via RHSA-2022:0841 https://access.redhat.com/errata/RHSA-2022:0841

Comment 24 errata-xmlrpc 2022-03-14 10:19:20 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.1 Update Services for SAP Solutions

Via RHSA-2022:0851 https://access.redhat.com/errata/RHSA-2022:0851

Comment 25 errata-xmlrpc 2022-03-14 10:48:24 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2022:0849 https://access.redhat.com/errata/RHSA-2022:0849

Comment 26 errata-xmlrpc 2022-03-17 16:28:03 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.1 Update Services for SAP Solutions

Via RHSA-2022:0958 https://access.redhat.com/errata/RHSA-2022:0958

Comment 27 errata-xmlrpc 2022-03-29 08:42:22 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.3 Advanced Update Support

Via RHSA-2022:1106 https://access.redhat.com/errata/RHSA-2022:1106

Comment 28 errata-xmlrpc 2022-03-29 08:50:47 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.4 Advanced Update Support

Via RHSA-2022:1104 https://access.redhat.com/errata/RHSA-2022:1104

Comment 29 errata-xmlrpc 2022-03-29 09:07:15 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.6 Update Services for SAP Solutions

Via RHSA-2022:1103 https://access.redhat.com/errata/RHSA-2022:1103

Comment 30 errata-xmlrpc 2022-03-29 09:54:41 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.6 Advanced Update Support
  Red Hat Enterprise Linux 7.6 Update Services for SAP Solutions
  Red Hat Enterprise Linux 7.6 Telco Extended Update Support

Via RHSA-2022:1107 https://access.redhat.com/errata/RHSA-2022:1107

Comment 32 errata-xmlrpc 2022-04-07 09:03:06 UTC

This issue has been addressed in the following products:

  Red Hat Virtualization 4 for Red Hat Enterprise Linux 7

Via RHSA-2022:1263 https://access.redhat.com/errata/RHSA-2022:1263

Comment 33 errata-xmlrpc 2022-04-12 15:37:18 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.7 Advanced Update Support
  Red Hat Enterprise Linux 7.7 Update Services for SAP Solutions
  Red Hat Enterprise Linux 7.7 Telco Extended Update Support

Via RHSA-2022:1324 https://access.redhat.com/errata/RHSA-2022:1324

Comment 34 errata-xmlrpc 2022-04-13 19:58:39 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.7 Update Services for SAP Solutions

Via RHSA-2022:1373 https://access.redhat.com/errata/RHSA-2022:1373

Comment 35 errata-xmlrpc 2022-04-19 16:11:32 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6 Extended Lifecycle Support

Via RHSA-2022:1417 https://access.redhat.com/errata/RHSA-2022:1417

Comment 38 Product Security DevOps Team 2022-05-11 13:15:26 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-2021-0920