Integer Overflow Vulnerability in Linux Kernel's ECDSA Implementation

CVE-2025-37984

What is CVE-2025-37984?

A vulnerability exists within the Linux kernel related to the ECDSA implementation that can lead to integer overflow due to improper handling of key sizes. Specifically, if an ECDSA implementation's ->key_size() callback returns a notably large value, the DIV_ROUND_UP() function could overflow. To mitigate this, a suggestion has been made to replace DIV_ROUND_UP() with a new macro, DIV_ROUND_UP_POW2(), which ensures safer calculations for key sizes. This fix is crucial for maintaining the integrity and security of cryptographic operations in affected versions of the Linux kernel.

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