Bug 2225201 (CVE-2023-3609)

Summary:	CVE-2023-3609 kernel: net/sched: cls_u32 component reference counter leak if tcf_change_indev() fails
Product:	[Other] Security Response	Reporter:	Alex <allarkin>
Component:	vulnerability	Assignee:	Nobody <nobody>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	acaringi, allarkin, bhu, chwhite, dbohanno, ddepaula, debarbos, dfreiber, dvlasenk, ezulian, hkrzesin, jarod, jburrell, jdenham, jfaracco, jferlan, jforbes, jlelli, joe.lawrence, jpoimboe, jshortt, jstancek, jwyatt, kcarcia, kernel-mgr, kpatch-maint, ldoskova, lgoncalv, lleshchi, lzampier, mvanderw, nmurray, ptalbert, qzhao, rhandlin, rkeshri, rogbas, rrobaina, rvrbovsk, rysulliv, scweaver, swood, tglozar, tyberry, vkumar, walters, wcosta, williams, wmealing, ycote, ymankad
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	Kernel 6.4-rc7	Doc Type:	If docs needed, set a value
Doc Text:	A double-free flaw was found in u32_set_parms in net/sched/cls_u32.c in the Network Scheduler component in the Linux kernel. This flaw allows a local attacker to use a failure event to mishandle the reference counter, leading to a local privilege escalation threat.	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:	2219411, 2225202, 2225483, 2225484, 2225485, 2225486, 2225487, 2225488, 2225489, 2225490, 2225491, 2225492, 2225493, 2225494, 2225495, 2225496, 2225497, 2225498, 2225500, 2225501, 2225502, 2225503, 2225505, 2225506, 2225507, 2225508, 2225509, 2225510, 2226868, 2226869, 2226870, 2226872, 2226873, 2225203
Bug Blocks:	2225185

Description Alex 2023-07-24 14:28:28 UTC

A flaw in the Linux Kernel found. A use-after-free vulnerability in the Linux kernel's net/sched: cls_u32 component can be exploited to achieve local privilege escalation. If tcf_change_indev() fails, u32_set_parms() will immediately return an error after incrementing or decrementing the reference counter in tcf_bind_filter(). If an attacker can control the reference counter and set it to zero, they can cause the reference to be freed, leading to a use-after-free vulnerability.

Reference:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?id=04c55383fa5689357bcdd2c8036725a55ed632bc