Bug 2063219 (CVE-2021-39686)

Summary:	CVE-2021-39686 kernel: race condition in the Android binder driver could lead to incorrect security checks
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	acaringi, adscvr, airlied, alciregi, bdettelb, bhu, brdeoliv, bskeggs, chwhite, crwood, dhoward, dvlasenk, fhrbata, fpacheco, hdegoede, hkrzesin, jarod, jarodwilson, jburrell, jeremy, jfaracco, jforbes, jglisse, jlelli, joe.lawrence, jonathan, josef, jshortt, jstancek, jwboyer, jwyatt, kcarcia, kernel-maint, kernel-mgr, lgoncalv, linville, lzampier, masami256, mchehab, nmurray, ptalbert, qzhao, rvrbovsk, scweaver, steved, vkumar, walters, williams, zulinx86
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	Kernel 5.14.18	Doc Type:	If docs needed, set a value
Doc Text:	A race condition was found in the Linux kernel Android binder driver. The driver is not included to the other kernels, apart from Android devices. This issue could allow a local user to crash the system or potentially escalate their privileges on the system.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2022-03-15 22:01:25 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:	2063220
Bug Blocks:	2063221

Description Guilherme de Almeida Suckevicz 2022-03-11 14:29:10 UTC

A race condition was discovered in the Android binder driver, that could lead to incorrect security checks. On systems where the binder driver is loaded, a local user could exploit this for privilege escalation.

References and upstream patches:
https://source.android.com/security/bulletin/2022-03-01
https://android.googlesource.com/kernel/common/+/d49297739550
https://android.googlesource.com/kernel/common/+/3af7a2f61023
https://android.googlesource.com/kernel/common/+/11db2de0af2a
https://android.googlesource.com/kernel/common/+/a4eacf3227bd

Comment 1 Guilherme de Almeida Suckevicz 2022-03-11 14:30:12 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 2063220]

Comment 2 Justin M. Forbes 2022-03-11 16:51:05 UTC

This was fixed for Fedora with the 5.14.18 stable kernel updates.

Comment 3 Rohit Keshri 2022-03-15 15:54:34 UTC

There was no source built with CONFIG_ANDROID_BINDER_IPC option in any of the shipped RHEL kernel versions.

Comment 6 Product Security DevOps Team 2022-03-15 22:01:21 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-2021-39686