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Findings

CVE-2025-37984

In the Linux kernel, the following vulnerability has been resolved: crypto: ecdsa - Harden against integer overflows in DIV_ROUND_UP() Herbert notes that DIV_ROUND_UP(…

Published May 20, 2025 · updated Oct 15, 2026 · linux linux kernel

In the Linux kernel, the following vulnerability has been resolved: crypto: ecdsa - Harden against integer overflows in DIV_ROUND_UP() Herbert notes that DIV_ROUND_UP() may overflow unnecessarily if an ecdsa implementation's ->key_size() callback returns an unusually large value. Herbert instead suggests (for a division by 8): X / 8 + !!(X & 7) Based on this formula, introduce a generic DIV_ROUND_UP_POW2() macro and use it in lieu of DIV_ROUND_UP() for ->key_size() return values. Additionally, use the macro in ecc_digits_from_bytes(), whose "nbytes" parameter is a ->key_size() return value in some instances, or a user-specified ASN.1 length in the case of ecdsa_get_signature_rs().

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. May 20, 2025 · NIST NVD

    Detected

    In the Linux kernel, the following vulnerability has been resolved: crypto: ecdsa - Harden against integer overflows in DIV_ROUND_UP() Herbert notes that DIV_ROUND_UP() may overflow unnecessarily if an ecdsa implementation's ->key_size() callback returns an unusually large value. Herbert instead suggests (for a division by 8): X / 8 + !!(X & 7) Based on this formula, introduce a generic DIV_ROUND_

  2. Oct 15, 2026 · NIST NVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: crypto: ecdsa - Harden against integer overflows in DIV_ROUND_UP() Herbert notes that DIV_ROUND_UP() may overflow unnecessarily if an ecdsa implementation's ->key_size() callback returns an unusually large value. Herbert instead suggests (for a division by 8): X / 8 + !!(X & 7) Based on this formula, introduce a generic DIV_ROUND_

Affected

  • cpe linux/linux kernelversion unspecified

Sources

  • CVE.orgVulnerability recordCVE-2025-37984

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-2025-37984

    In the Linux kernel, the following vulnerability has been resolved: crypto: ecdsa - Harden against integer overflows in DIV_ROUND_UP() Herbert notes that DIV_ROUND_UP() may overflow unnecessarily if an ecdsa implementation's ->key_size() callback returns an unusually large valu

    nvd.nist.gov

References

CVE-2025-37984 · ZeroDay Findings