CVE-2025-39921

MEDIUM
Published Oct 1, 2025 Modified Jan 14, 2026

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.

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CVSS v3.1 Score

5.5
MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected Products

Vendor Product
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel

References

Frequently Asked Questions

What is CVE-2025-39921? +
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. It has a CVSS v3.1 base score of 5.5 (MEDIUM).
How severe is CVE-2025-39921? +
CVE-2025-39921 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.
What products are affected by CVE-2025-39921? +
CVE-2025-39921 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2025-39921? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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