Bug 2492326 (CVE-2026-53110)

Summary: CVE-2026-53110 kernel: s390/bpf: Zero-extend bpf prog return values and kfunc arguments
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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 BPF (Berkeley Packet Filter) JIT (Just-In-Time) compiler for the s390x architecture. The system's Application Binary Interface (ABI) requires that unsigned arguments and return values be zero-extended. However, the BPF JIT compiler incorrectly performed only sign extension. This could lead to unexpected behavior or data integrity issues when BPF programs interact with kernel functions on s390x systems.
 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 2026-06-24 18:05:55 UTC 
In the Linux kernel, the following vulnerability has been resolved:

s390/bpf: Zero-extend bpf prog return values and kfunc arguments

s390x ABI requires callers to zero-extend unsigned arguments and
sign-extend signed arguments, and callees to zero-extend unsigned
return values and sign-extend signed return values.

s390 BPF JIT currently implements only sign extension. Fix this
omission and implement zero extension too.
Comment 1 Keith Grant 2026-06-26 18:16:24 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062414-CVE-2026-53110-c958@gregkh/T