Bug 1903291

Summary:	kernel: insecure handling of root directory for path lookups in fs/io_uring.c
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED DUPLICATE	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	acaringi, adscvr, airlied, bhu, blc, bmasney, brdeoliv, bskeggs, dhoward, dvlasenk, fhrbata, hdegoede, hkrzesin, itamar, jarodwilson, jeremy, jforbes, jglisse, jlelli, jonathan, josef, jshortt, jstancek, jwboyer, kcarcia, kernel-maint, kernel-mgr, lgoncalv, linville, masami256, mchehab, mjg59, mlangsdo, nmurray, pmatouse, ptalbert, qzhao, rvrbovsk, steved, walters, 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 flaw was found in the Linux kernel. A process inside a mounted namespace can escape to unintended filesystem locations during path lookups. The highest threat from this vulnerability is to data integrity.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-12-03 11:57:54 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:	1903293
Bug Blocks:	1903292

Description Guilherme de Almeida Suckevicz 2020-12-01 19:04:40 UTC

An issue was discovered in fs/io_uring.c in the Linux kernel before 5.6. It unsafely handles the root directory during path lookups, and thus a process inside a mount namespace can escape to unintended filesystem locations.

Reference:
https://bugs.chromium.org/p/project-zero/issues/detail?id=2011

Upstream patch:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ff002b30181d30cdfbca316dadd099c3ca0d739c

Comment 1 Guilherme de Almeida Suckevicz 2020-12-01 19:09:08 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1903293]

Comment 2 Justin M. Forbes 2020-12-02 14:28:42 UTC

This was fixed for Fedora with the 5.6 kernel rebases.

Comment 3 Petr Matousek 2020-12-10 12:26:47 UTC


*** This bug has been marked as a duplicate of bug 1875818 ***