Bug 2414517 (CVE-2025-40129)

Summary: CVE-2025-40129 kernel: sunrpc: fix null pointer dereference on zero-length checksum
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedKeywords: Security
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OS: Linux   
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Description OSIDB Bzimport 2025-11-12 11:04:59 UTC 
In the Linux kernel, the following vulnerability has been resolved:

sunrpc: fix null pointer dereference on zero-length checksum

In xdr_stream_decode_opaque_auth(), zero-length checksum.len causes
checksum.data to be set to NULL. This triggers a NPD when accessing
checksum.data in gss_krb5_verify_mic_v2(). This patch ensures that
the value of checksum.len is not less than XDR_UNIT.
Comment 1 Alexander B 2025-11-13 13:03:15 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025111254-CVE-2025-40129-fbb4@gregkh/T