Bug 2248755 (CVE-2023-6039)

Summary:	CVE-2023-6039 kernel: use-after-free in drivers/net/usb/lan78xx.c in lan78xx_disconnect
Product:	[Other] Security Response	Reporter:	Rohit Keshri <rkeshri>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, allarkin, bhu, chwhite, cye, cyin, dbohanno, debarbos, dfreiber, dvlasenk, ezulian, hkrzesin, jarod, jburrell, jdenham, jfaracco, jforbes, jlelli, joe.lawrence, jshortt, jstancek, jwyatt, kcarcia, ldoskova, lgoncalv, lzampier, mstowell, nmurray, ptalbert, rogbas, rparrazo, rrobaina, rvrbovsk, rysulliv, scweaver, tglozar, tyberry, vkumar, wcosta, williams, wmealing, ycote, ykopkova, zhijwang
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	Kernel 6.5-rc5	Doc Type:	If docs needed, set a value
Doc Text:	A use-after-free flaw was found in lan78xx_disconnect in drivers/net/usb/lan78xx.c in the network sub-component, net/usb/lan78xx in the Linux Kernel. This flaw allows a local attacker to crash the system when the LAN78XX USB device detaches.	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:
Bug Blocks:	2248754

Description Rohit Keshri 2023-11-08 19:12:02 UTC

There are use-after-free vulnerabilities in drivers/net/usb/lan78xx.c of 
linux that allow attacker to crash linux kernel when LAN78XX USB device 
is detaching.

The timer dev->stat_monitor can schedule the delayed work dev->wq and
the delayed work dev->wq can also arm the dev->stat_monitor timer.

When the device is detaching, the net_device will be deallocated. But
the net_device private data could still be dereferenced in delayed work
or timer handler. As a result, the UAF bugs will happen.

Refer:
https://github.com/torvalds/linux/commit/1e7417c188d0a83fb385ba2dbe35fd2563f2b6f3