Bug 2389479 (CVE-2025-38611)

Summary: CVE-2025-38611 kernel: vmci: Prevent the dispatching of uninitialized payloads
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: 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 2025-08-19 18:03:00 UTC 
In the Linux kernel, the following vulnerability has been resolved:

vmci: Prevent the dispatching of uninitialized payloads

The reproducer executes the host's unlocked_ioctl call in two different
tasks. When init_context fails, the struct vmci_event_ctx is not fully
initialized when executing vmci_datagram_dispatch() to send events to all
vm contexts. This affects the datagram taken from the datagram queue of
its context by another task, because the datagram payload is not initialized
according to the size payload_size, which causes the kernel data to leak
to the user space.

Before dispatching the datagram, and before setting the payload content,
explicitly set the payload content to 0 to avoid data leakage caused by
incomplete payload initialization.
Comment 1 Jon Moroney 2025-08-19 23:24:22 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025081923-CVE-2025-38611-e9f6@gregkh/T