CVE-2023-53680: NFSD: Avoid calling OPDESC() with ops->opnum == OP_ILLEGAL

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-10-07 · updated 2026-10-28
Weakness: CWE-787

Description

In the Linux kernel, the following vulnerability has been resolved: NFSD: Avoid calling OPDESC() with ops->opnum == OP_ILLEGAL OPDESC() simply indexes into nfsd4_ops[] by the op's operation number, without range checking that value. It assumes callers are careful to avoid calling it with an out-of-bounds opnum value. nfsd4_decode_compound() is not so careful, and can invoke OPDESC() with opnum set to OP_ILLEGAL, which is 10044 -- well beyond the end of nfsd4_ops[].

Affected products

Linux kernel: from 4.14 before 5.10.220; from 5.11 before 5.15.107; from 5.16 before 6.1.24; from 6.2 before 6.2.11; 6.3-rc1, 6.3-rc2, 6.3-rc3, 6.3-rc4, 6.3-rc5 — fixed in 5.10.220, 5.15.107, 6.1.24, 6.2.11

How to fix

Upgrade to a fixed version: Linux kernel 5.10.220, 5.15.107, 6.1.24, 6.2.11. Check the vendor advisory for mitigations.

References

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