Bug 2087568 (CVE-2023-1838)

Summary:	CVE-2023-1838 kernel: Possible use-after-free since the two fdget() during vhost_net_set_backend()
Product:	[Other] Security Response	Reporter:	Sandipan Roy <saroy>
Component:	vulnerability	Assignee:	Nobody <nobody>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, adscvr, airlied, alciregi, allarkin, bhu, brdeoliv, chwhite, crwood, ddepaula, dvlasenk, hdegoede, hkrzesin, hpa, jarod, jarodwilson, jburrell, jfaracco, jferlan, jforbes, jglisse, jlelli, joe.lawrence, jonathan, josef, jshortt, jstancek, jwboyer, jwyatt, kcarcia, kernel-maint, kernel-mgr, lgoncalv, linville, lzampier, masami256, mchehab, nmurray, ptalbert, qzhao, rkeshri, rvrbovsk, scweaver, steved, tyberry, vkumar, walters, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel 5.18 25	Doc Type:	If docs needed, set a value
Doc Text:	A use-after-free flaw was found in vhost_net_set_backend in drivers/vhost/net.c in the virtio network subcomponent in the Linux kernel due to a double fget. This issue could allow a local attacker to crash the system, and could lead to a kernel information leak problem.	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:	2111141, 2111142, 2111143, 2111144
Bug Blocks:	2087569

Description Sandipan Roy 2022-05-18 04:39:37 UTC

A use-after-free flaw was found in vhost_net_set_backend in drivers/vhost/net.c in virtio network subcomponent in the Linux kernel due to a double fget. This flaw could allow a local attacker to crash the system, and could even lead to a kernel information leak problem.

The descriptor table is a shared resource; two fget() on the same descriptor may return different struct file references. get_tap_ptr_ring() is called after we'd found (and pinned) the socket we'll be using and it tries to find the private tun/tap data structures associated with it. Redoing the lookup by the same file descriptor we'd used to get the socket is racy - we need to same struct file.

Patch Reference:
https://lore.kernel.org/netdev/20220516084213.26854-1-jasowang@redhat.com/T/

Comment 17 errata-xmlrpc 2024-01-24 16:42:29 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.6 Extended Update Support

Via RHSA-2024:0412 https://access.redhat.com/errata/RHSA-2024:0412

Comment 18 errata-xmlrpc 2024-01-30 13:21:04 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.8 Extended Update Support

Via RHSA-2024:0575 https://access.redhat.com/errata/RHSA-2024:0575

Comment 20 errata-xmlrpc 2024-02-20 12:27:47 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2024:0881 https://access.redhat.com/errata/RHSA-2024:0881

Comment 21 errata-xmlrpc 2024-02-20 12:32:58 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2024:0897 https://access.redhat.com/errata/RHSA-2024:0897