# CVE-2025-39921: linux: In the Linux kernel, the following vulnerability has been resolved:  spi: microchip-core-qspi: stop checking viabilit...

CVE-2025-39921 is fixed in linux on 1 platform by DEBIAN-CVE-2025-39921 (version 6.16.6-1), released October 1, 2025. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2025-39921
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0019
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 1, 2025

## Description

In the Linux kernel, the following vulnerability has been resolved:  spi: microchip-core-qspi: stop checking viability of op->max_freq in supports_op callback  In commit 13529647743d9 ("spi: microchip-core-qspi: Support per spi-mem operation frequency switches") the logic for checking the viability of op->max_freq in mchp_coreqspi_setup_clock() was copied into mchp_coreqspi_supports_op(). Unfortunately, op->max_freq is not valid when this function is called during probe but is instead zero. Accordingly, baud_rate_val is calculated to be INT_MAX due to division by zero, causing probe of the attached memory device to fail.  Seemingly spi-microchip-core-qspi was the only driver that had such a modification made to its supports_op callback when the per_op_freq capability was added, so just remove it to restore prior functionality.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 14 | 6.16.6-1 | [DEBIAN-CVE-2025-39921](https://patchblox.com/security/data/fix/linux/debian-cve-2025-39921.md) | Oct 1, 2025 |

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Data as of 2026-11-10T01:44:33Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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