Bug 2397554 (CVE-2025-39872)

Summary: CVE-2025-39872 kernel: hsr: hold rcu and dev lock for hsr_get_port_ndev
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: unspecifiedKeywords: Security
Target Milestone: ---   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
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 2025-09-23 07:01:19 UTC 
In the Linux kernel, the following vulnerability has been resolved:

hsr: hold rcu and dev lock for hsr_get_port_ndev

hsr_get_port_ndev calls hsr_for_each_port, which need to hold rcu lock.
On the other hand, before return the port device, we need to hold the
device reference to avoid UaF in the caller function.
Comment 1 Jon Moroney 2025-09-23 17:39:07 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025092300-CVE-2025-39872-5102@gregkh/T