Bug 1786174 (CVE-2019-19769)

Summary:	CVE-2019-19769 kernel: use-after-free in perf_trace_lock_acquire related to include/trace/events/lock.h
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, airlied, bdettelb, bhu, blc, brdeoliv, bskeggs, dhoward, dvlasenk, esammons, fhrbata, hdegoede, hkrzesin, iboverma, ichavero, itamar, jarodwilson, jeremy, jforbes, jglisse, jlelli, john.j5live, jonathan, josef, jross, jschorr, jshortt, jstancek, jwboyer, kernel-maint, kernel-mgr, labbott, lgoncalv, linville, masami256, matt, mchehab, mcressma, mjg59, mlangsdo, mszeredi, nmurray, qzhao, rkeshri, rt-maint, rvrbovsk, sgrubb, steved, williams
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 use-after-free flaw was found when wakeup a waiter was in race in the locks_delete_block in fs/locks.c function in the Linux kernel's filesystem. A local attacker with a special user account (or root) may cause a denial of service, a system crash, or a leak in the internal kernel information.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-07-06 13:27:37 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:	1786175, 1834786, 1834787, 1834788
Bug Blocks:	1786176

Description Guilherme de Almeida Suckevicz 2019-12-23 17:52:50 UTC

An use-after-free (UAF)  flaw was found when wakeup a waiter was in race  in locks_delete_block in fs/locks.c in the Linux kernel's filesystem.  A local attacker with a special user account (or root) may cause a denial of access (DoS), a system crash or leak internal kernel information.

Reference:
https://bugzilla.kernel.org/show_bug.cgi?id=205705

Comment 1 Guilherme de Almeida Suckevicz 2019-12-23 17:54:41 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1786175]

Comment 8 Rohit Keshri 2020-05-12 12:20:46 UTC

Mitigation:

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Comment 12 Rohit Keshri 2020-07-01 12:29:21 UTC

This exploit is only possible with a special privileged user account locally (AV:L, PR:H) so in the initial i set it to Priority:Low
  
Since this is a UAF problem which will expose kernel address which is readable (C:H) and modifiable (I:H) (by a special user along with root) set Priority: Medium.

Comment 15 Product Security DevOps Team 2020-07-06 13:27:37 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-2019-19769