Bug 2124061

Summary:	kernel: eBPF verifier bug: Mishandling in release_reg_references() cause a PTR leak vulnerability
Product:	[Other] Security Response	Reporter:	Alex <allarkin>
Component:	vulnerability	Assignee:	Nobody <nobody>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, adscvr, airlied, alciregi, bhu, brdeoliv, bskeggs, chwhite, ddepaula, debarbos, dfreiber, dvlasenk, ezulian, hdegoede, hkrzesin, hpa, jarod, jarodwilson, jburrell, jfaracco, jferlan, jforbes, jglisse, jlelli, joe.lawrence, josef, jshortt, jstancek, jwboyer, jwyatt, kcarcia, kernel-maint, kernel-mgr, lgoncalv, linville, lleshchi, lzampier, masami256, mchehab, nmurray, ptalbert, qzhao, rogbas, rvrbovsk, scweaver, steved, swood, tyberry, vkumar, 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 possible leak of data in the Linux kernel's BPF subsystem was found in the way user triggers release_reg_references() of BPF in the way that release fails. A local user could use this flaw to get unprivileged access to some data or potentially escalate their privileges on the system.	Story Points:	---
Clone Of:		Environment:
Last Closed:		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:	2151552, 2151560, 2151561, 2151562, 2151563
Bug Blocks:	2109540

Description Alex 2022-09-04 11:17:44 UTC

A flaw found in the Linux Kernel in kernel/bpf/verifier.c.
Leak of data from pointer possible because of the possibility to call BPF_FUNC_ringbuf_discard after BPF_FUNC_ringbuf_reserve where SCALAR_VALUE assigned to data previously contained a pointer value at runtime.

Reference:
https://lore.kernel.org/bpf/8f4c3e52-ce86-cbfc-5e76-884596ec11d7@fb.com/

Comment 1 Alex 2022-12-07 13:50:45 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 2151552]