Bug 2482640 (CVE-2026-46234)

Summary: CVE-2026-46234 kernel: vsock: fix buffer size clamping order
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 vsock component. This vulnerability stems from an incorrect order in which buffer sizes are validated, allowing a local user to set a minimum buffer size larger than the maximum. This can cause the socket's memory to exceed its defined boundaries, potentially leading to resource exhaustion or system instability, which could result in a Denial of Service (DoS).
 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 2026-05-28 11:07:11 UTC 
In the Linux kernel, the following vulnerability has been resolved:

vsock: fix buffer size clamping order

In vsock_update_buffer_size(), the buffer size was being clamped to the
maximum first, and then to the minimum. If a user sets a minimum buffer
size larger than the maximum, the minimum check overrides the maximum
check, inverting the constraint.

This breaks the intended socket memory boundaries by allowing the
vsk->buffer_size to grow beyond the configured vsk->buffer_max_size.

Fix this by checking the minimum first, and then the maximum. This
ensures the buffer size never exceeds the buffer_max_size.
Comment 1 Keith Grant 2026-05-28 12:19:24 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026052840-CVE-2026-46234-bed5@gregkh/T