Bug 2516881 (CVE-2026-74425)

Summary: CVE-2026-74425 kernel: afs: handle CB.InitCallBackState3 requests without a server record
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: 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 AFS (Andrew File System) cache manager. The `CB.InitCallBackState3` handler did not properly verify the presence of an associated server record for incoming callback requests. This could lead to unexpected system behavior or instability if a request was processed without the necessary peer state.
 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 2026-08-15 06:38:21 UTC 
In the Linux kernel, the following vulnerability has been resolved:

afs: handle CB.InitCallBackState3 requests without a server record

The cache manager callback path now attaches the server record to an
incoming call through the rxrpc peer's app data.  That association is
not guaranteed to exist for every callback request, and most callback
handlers already tolerate that case.

Make CB.InitCallBackState3 follow the same pattern by checking whether a
server record was attached before using it.  If the peer is not mapped
to a server record, trace the request and ignore it, matching the
existing behaviour for other unmatched callback requests.

This keeps the callback handler consistent with the rest of the cache
manager service and avoids depending on peer state that may not be
available for a given request.
Comment 1 Keith Grant 2026-08-20 22:15:48 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081513-CVE-2026-74425-6b8b@gregkh/T