Bug 1481149 (CVE-2017-10663)

Summary:	CVE-2017-10663 kernel: Missing sanity check for segno and blkoff read
Product:	[Other] Security Response	Reporter:	Adam Mariš <amaris>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	agordeev, aquini, bhu, blc, dhoward, esammons, fhrbata, gansalmon, hkrzesin, hwkernel-mgr, iboverma, ichavero, itamar, jforbes, jkacur, jonathan, jross, jwboyer, kernel-maint, kernel-mgr, labbott, lgoncalv, lwang, madhu.chinakonda, matt, mchehab, mcressma, mguzik, mlangsdo, nmurray, pholasek, plougher, rt-maint, rvrbovsk, slawomir, vdronov, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	The sanity_check_ckpt function in fs/f2fs/super.c in the Linux kernel before version 4.12.4 does not validate the blkoff and segno arrays. This allows an unprivileged, local user to cause a system panic and DoS. Due to the nature of the flaw, privilege escalation cannot be fully ruled out, although we believe it is unlikely.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2017-08-27 15:39:55 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:	1481153
Bug Blocks:	1481154

Description Adam Mariš 2017-08-14 08:39:08 UTC

The sanity_check_ckpt function in fs/f2fs/super.c in the Linux kernel before 4.12.4 does not validate the blkoff and segno arrays, which allows an unprivileged local user to cause a system panic and DoS. Due to the nature of the flaw, privilege escalation cannot be fully ruled out, although we believe it is unlikely.

References:

https://source.android.com/security/bulletin/2017-08-01#kernel-components

https://sourceforge.net/p/linux-f2fs/mailman/message/35835945/

Upstream patch:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=15d3042a937c13f5d9244241c7a9c8416ff6e82a

Comment 1 Adam Mariš 2017-08-14 08:47:18 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1481153]

Comment 4 Vladis Dronov 2017-08-27 15:39:55 UTC

Statement:

This issue does not affect the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 5, 6, 7 and Red Hat Enterprise MRG 2 as the code with the flaw is not built and shipped with the products listed.

Comment 5 Justin M. Forbes 2018-01-29 16:30:32 UTC

This was fixed for Fedora with the 4.12.4 stable updates