CVE-2025-21734: linux kernel Memory Corruption — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: misc: fastrpc: Fix copy buffer page size For non-registered buffer, fastrpc driver copies the buffer and pass it to the remote subsystem. There is a problem with current implementation of page size calculation which is not considering the offset in the calculation. This might lead to passing of improper and out-of-bounds page size which could result in memory issue. Calculate page start and page end using the offset adjusted address instead of absolute address.

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CVSS v3.1 Score

7.8

HIGH

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

Weakness Type (CWE)

CWE-787 Out-of-bounds Write

Affected Products

Vendor	Product	Versions
linux	linux_kernel	5.2 — 6.1.129
linux	linux_kernel	6.2 — 6.6.78
linux	linux_kernel	6.7 — 6.12.14
linux	linux_kernel	6.13 — 6.13.3

References

Advisories & Patches

https://git.kernel.org/stable/c/24a79c6bc8de763f7c50f4f84f8b0c183bc25a51 https://git.kernel.org/stable/c/c0464bad0e85fcd5d47e4297d1e410097c979e55 https://git.kernel.org/stable/c/c3f7161123fcbdc64e90119ccce292d8b66281c4 https://git.kernel.org/stable/c/c56ba3ea8e3c9a69a992aad18f7a65e43e51d623 https://git.kernel.org/stable/c/e966eae72762ecfdbdb82627e2cda48845b9dd66

Other References

https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html

Frequently Asked Questions

What is CVE-2025-21734? +

In the Linux kernel, the following vulnerability has been resolved: misc: fastrpc: Fix copy buffer page size For non-registered buffer, fastrpc driver copies the buffer and pass it to the remote subsystem. There is a problem with current implementation of page size calculation which is not considering the offset in the calculation. This might lead to passing of improper and out-of-bounds page size which could result in memory issue. Calculate page start and page end using the offset adjusted address instead of absolute address. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2025-21734? +

CVE-2025-21734 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-21734? +

CVE-2025-21734 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-2025-21734? +

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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