Bug 1529123 (CVE-2017-17863)

Summary:	CVE-2017-17863 kernel: integer overflow in static int check_alu_op function in bpf/verifier.c
Product:	[Other] Security Response	Reporter:	Pedro Sampaio <psampaio>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	airlied, ajax, aquini, bhu, blc, bskeggs, dhoward, ewk, fhrbata, hdegoede, hkrzesin, hwkernel-mgr, iboverma, ichavero, itamar, jarodwilson, jforbes, jglisse, jkacur, john.j5live, jolsa, jonathan, josef, jross, jwboyer, kernel-maint, kernel-mgr, labbott, lgoncalv, linville, matt, mchehab, mcressma, mjg59, mlangsdo, nmurray, plougher, ppandit, psampaio, rt-maint, rvrbovsk, skozina, 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:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-06-08 03:34:56 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:	1529125, 1535005
Bug Blocks:	1528364

Description Pedro Sampaio 2017-12-26 14:33:08 UTC

kernel/bpf/verifier.c in the Linux kernel 4.9.x through 4.9.71 does not check the relationship between pointer values and the BPF stack, which allows local users to cause a denial of service (integer overflow or invalid memory access) or possibly have unspecified other impact.

References:

https://anonscm.debian.org/cgit/kernel/linux.git/tree/debian/patches/bugfix/all/bpf-reject-out-of-bounds-stack-pointer-calculation.patch?h=stretch-security
https://www.spinics.net/lists/stable/msg206985.html

Comment 1 Pedro Sampaio 2017-12-26 14:48:32 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1529125]

Comment 3 Prasad Pandit 2018-01-18 05:24:36 UTC

Statement:

This issue does not affect the versions of the kernel package as shipped with Red Hat Enterprise Linux 5, 6, 7 and Red Hat Enterprise MRG 2.

Comment 5 Jiri Olsa 2019-01-09 09:02:53 UTC

(In reply to Pedro Sampaio from comment #0)
> kernel/bpf/verifier.c in the Linux kernel 4.9.x through 4.9.71 does not
> check the relationship between pointer values and the BPF stack, which
> allows local users to cause a denial of service (integer overflow or invalid
> memory access) or possibly have unspecified other impact.
> 
> References:
> 
> https://anonscm.debian.org/cgit/kernel/linux.git/tree/debian/patches/bugfix/
> all/bpf-reject-out-of-bounds-stack-pointer-calculation.patch?h=stretch-
> security
> https://www.spinics.net/lists/stable/msg206985.html

based on info from BZ1529120 is the requested 4.9 patch:
  bpf: reject out-of-bounds stack pointer calculation

counterpart to upstream:
  https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=179d1c5602997fef5a940c6ddcf31212cbfebd14.

please let me know if that's correct or provide nother upstream patch

thanks,
jirka

Comment 6 Pedro Sampaio 2019-01-09 17:03:49 UTC

Yes, I could confirm that the 4.9 patch aims to reflect the same behavior of this counterpart patch on the newer upstream code.