Bug 2039911 (CVE-2021-45485)

Summary:	CVE-2021-45485 kernel: information leak in the IPv6 implementation
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, adscvr, airlied, alciregi, bhu, brdeoliv, bskeggs, chwhite, crwood, dhoward, dvlasenk, fhrbata, fpacheco, hdegoede, hkrzesin, jarod, jarodwilson, jburrell, jeremy, jfaracco, jforbes, jglisse, jlelli, jonathan, josef, jshortt, jstancek, jwboyer, kcarcia, kernel-maint, kernel-mgr, lgoncalv, linville, lzampier, masami256, mchehab, nmurray, ptalbert, qzhao, rvrbovsk, scweaver, steved, vkumar, walters, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel 5.14 rc1	Doc Type:	If docs needed, set a value
Doc Text:	An information leak flaw was found in the Linux kernel’s IPv6 implementation in the __ipv6_select_ident in net/ipv6/output_core.c function. The use of a small hash table in IP ID generation allows a remote attacker to reveal sensitive information.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2022-05-11 14:45:59 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:	2039912, 2040158, 2040159, 2126325, 2126326
Bug Blocks:	2039913

Description Guilherme de Almeida Suckevicz 2022-01-12 17:39:27 UTC

In the IPv6 implementation in the Linux kernel before 5.13.3, net/ipv6/output_core.c has an information leak because of certain use of a hash table which, although big, doesn't properly consider that IPv6-based attackers can typically choose among many IPv6 source addresses.

Reference and upstream patch:
https://arxiv.org/pdf/2112.09604.pdf
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=62f20e068ccc50d6ab66fdb72ba90da2b9418c99

Comment 1 Guilherme de Almeida Suckevicz 2022-01-12 17:40:10 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 2039912]

Comment 7 Justin M. Forbes 2022-01-14 15:42:28 UTC

This was fixed for Fedora users with the 5.12.18 stable kernel update.

Comment 9 errata-xmlrpc 2022-05-10 14:40:55 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2022:1975 https://access.redhat.com/errata/RHSA-2022:1975

Comment 10 errata-xmlrpc 2022-05-10 14:46:59 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2022:1988 https://access.redhat.com/errata/RHSA-2022:1988

Comment 11 Product Security DevOps Team 2022-05-11 14:45:56 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-2021-45485

Comment 14 errata-xmlrpc 2022-10-18 08:04:06 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.4 Extended Update Support

Via RHSA-2022:6991 https://access.redhat.com/errata/RHSA-2022:6991

Comment 15 errata-xmlrpc 2022-10-18 08:14:23 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.4 Extended Update Support

Via RHSA-2022:6983 https://access.redhat.com/errata/RHSA-2022:6983