cve/2025/CVE-2025-37984.md

CVE-2025-37984

Description

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 ecdsaimplementation'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 anduse 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 auser-specified ASN.1 length in the case of ecdsa_get_signature_rs().

POC

Reference

No PoCs from references.

Github

• https://github.com/w4zu/Debian_security