Bug 2124475 (CVE-2022-3586)

Summary:	CVE-2022-3586 kernel: net scheduler use-after-free information disclosure vulnerability
Product:	[Other] Security Response	Reporter:	Mauro Matteo Cascella <mcascell>
Component:	vulnerability	Assignee:	Nobody <nobody>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, allarkin, bhu, brdeoliv, chwhite, crwood, ddepaula, debarbos, dvlasenk, ezulian, hkrzesin, jarod, jburrell, jfaracco, jferlan, jforbes, jlelli, joe.lawrence, jshortt, jstancek, jwyatt, kcarcia, kernel-mgr, lgoncalv, lzampier, nmurray, ptalbert, qzhao, rvrbovsk, scweaver, shuali, tyberry, vkumar, walters, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel 6.0	Doc Type:	If docs needed, set a value
Doc Text:	A flaw was found in the Linux kernel’s networking code. A use-after-free was found in the way the sch_sfb enqueue function used the socket buffer (SKB) cb field after the same SKB had been enqueued (and freed) into a child qdisc. This flaw allows a local, unprivileged user to to disclose sensitive information or crash the system, causing a denial of service.	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:	2124490, 2124492, 2124493, 2124494
Bug Blocks:	2121242

Description Mauro Matteo Cascella 2022-09-06 09:24:58 UTC

When the GSO splitting feature of sch_cake is enabled, GSO superpackets will be broken up and the resulting segments enqueued in place of the original skb. In this case, CAKE calls consume_skb() on the original skb, but still returns NET_XMIT_SUCCESS. This can confuse parent qdiscs into assuming the original skb still exists, when it really has been freed.

Upstream patch & commit:
https://lore.kernel.org/all/87wnao2ha3.fsf@toke.dk/T/
https://github.com/torvalds/linux/commit/9efd23297cca