Bug 2492824 (CVE-2026-53157)

Summary:	CVE-2026-53157 kernel: net: phonet: free phonet_device after RCU grace period
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's phonet networking subsystem. This vulnerability occurs because a phonet device is freed immediately after being removed from a list, while other parts of the kernel (RCU readers) may still hold a pointer to the freed memory. This can lead to a use-after-free condition, potentially allowing a local attacker to cause a denial of service or escalate privileges.	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:

Description OSIDB Bzimport 2026-06-25 10:07:41 UTC

In the Linux kernel, the following vulnerability has been resolved:

net: phonet: free phonet_device after RCU grace period

phonet_device_destroy() removes a phonet_device from the per-net device
list with list_del_rcu(), but frees it immediately. RCU readers walking
the same list can still hold a pointer to the object after it has been
removed, leading to a slab-use-after-free.

Use kfree_rcu(), matching the lifetime rule already used by
phonet_address_del() for the same object type.

Comment 1 Keith Grant 2026-06-26 01:17:17 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062548-CVE-2026-53157-7e36@gregkh/T