Bug 2239848 (CVE-2023-42756)

Summary:	CVE-2023-42756 kernel: netfilter: race condition between IPSET_CMD_ADD and IPSET_CMD_SWAP
Product:	[Other] Security Response	Reporter:	Patrick Del Bello <pdelbell>
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, dbohanno, debarbos, dfreiber, dvlasenk, ezulian, hkrzesin, jarod, jburrell, jdenham, jfaracco, jforbes, jlelli, joe.lawrence, jshortt, jstancek, jwyatt, kcarcia, ldoskova, lgoncalv, lzampier, mcascell, nmurray, ptalbert, rogbas, rrobaina, rvrbovsk, rysulliv, scweaver, security-response-team, tglozar, tyberry, vkumar, wcosta, williams, wmealing, ycote
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel 6.6-rc3	Doc Type:	If docs needed, set a value
Doc Text:	A flaw was found in the Netfilter subsystem of the Linux kernel. A race condition between IPSET_CMD_ADD and IPSET_CMD_SWAP can lead to a kernel panic due to the invocation of `__ip_set_put` on a wrong `set`. This issue may allow a local user to crash 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:	2241163
Bug Blocks:	2238729

Description Patrick Del Bello 2023-09-20 13:56:37 UTC

A flaw was found under netfilter subsystem. Race between IPSET_CMD_ADD and IPSET_CMD_SWAP. No lock is hold when it does the `cond_resched()`. As a result, `ip_set_ref_lock` (in thread 2) can swap the set with another when thread 1 is doing the `cond_resched()`. Which might lead to a local Denial of Service (DoS).

Comment 4 Mauro Matteo Cascella 2023-09-28 09:35:03 UTC

Reference:
https://seclists.org/oss-sec/2023/q3/242

Upstream fix:
https://github.com/torvalds/linux/commit/7433b6d2afd512d04398c73aa984d1e285be125b

Comment 6 Mauro Matteo Cascella 2023-09-28 10:21:37 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 2241163]

Comment 10 errata-xmlrpc 2024-04-30 10:13:57 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2024:2394 https://access.redhat.com/errata/RHSA-2024:2394