Bug 1699856 (CVE-2019-11190)

Summary:	CVE-2019-11190 kernel: ASLR bypass for setuid binaries due to late install_exec_creds()
Product:	[Other] Security Response	Reporter:	Vladis Dronov <vdronov>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	airlied, bskeggs, hdegoede, ichavero, itamar, jarodwilson, jeremy, jforbes, jglisse, john.j5live, jonathan, josef, jwboyer, kernel-maint, labbott, linville, mchehab, mjg59, steved
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 in the load_elf_binary() function in the Linux kernel allows a local attacker to leak the base address of .text and stack sections for setuid binaries and bypass ASLR because install_exec_creds() is called too late in this function.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-03-31 22:33:52 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:	1700360, 1700361, 1700362, 2117200
Bug Blocks:	1696601

Description Vladis Dronov 2019-04-15 11:53:32 UTC

A flaw in the load_elf_binary() function in the Linux kernel allows a local attacker to leak the base address of .text and stack sections for setuid binaries and thus to bypass ASLR because install_exec_creds() is called too late in this function.

References:

https://seclists.org/oss-sec/2019/q2/9

https://www.openwall.com/lists/oss-security/2019/04/03/4

An upstream patch:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9f834ec18defc369d73ccf9e87a2790bfa05bf46

Comment 3 Vladis Dronov 2019-04-16 11:39:55 UTC

Notes:

In our research we was not able to reproduce the issue with the standard RHEL-7 kernel, but only with modified kernel with specially inserted delay, which widens a race window. This means the race condition still exists, i.e. the system is still vulnerable, but it is hard to hit it.

Comment 5 errata-xmlrpc 2020-03-31 19:11:28 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2020:1016 https://access.redhat.com/errata/RHSA-2020:1016

Comment 6 errata-xmlrpc 2020-03-31 19:20:25 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2020:1070 https://access.redhat.com/errata/RHSA-2020:1070

Comment 7 Product Security DevOps Team 2020-03-31 22:33:52 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-2019-11190