CVE-2025-21947: linux kernel — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix type confusion via race condition when using ipc_msg_send_request req->handle is allocated using ksmbd_acquire_id(&ipc_ida), based on ida_alloc. req->handle from ksmbd_ipc_login_request and FSCTL_PIPE_TRANSCEIVE ioctl can be same and it could lead to type confusion between messages, resulting in access to unexpected parts of memory after an incorrect delivery. ksmbd check type of ipc response but missing add continue to check next ipc reponse.

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CVSS v3.1 Score

8.1

HIGH

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

Weakness Type (CWE)

CWE-362 CWE-362

Affected Products

Vendor	Product	Versions
linux	linux_kernel	5.15 — 6.1.131
linux	linux_kernel	6.2 — 6.6.83
linux	linux_kernel	6.7 — 6.12.19
linux	linux_kernel	6.13 — 6.13.7
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/1e8833c03a38e1d5d5df6484e3f670a2fd38fb76 https://git.kernel.org/stable/c/3cb2b2e41541fe6f9cc55ca22d4c0bd260498aea https://git.kernel.org/stable/c/6321bbda4244b93802d61cfe0887883aae322f4b https://git.kernel.org/stable/c/76861630b29e51373e73e7b00ad0d467b6941162 https://git.kernel.org/stable/c/e2ff19f0b7a30e03516e6eb73b948e27a55bc9d2

Other References

https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html

Frequently Asked Questions

What is CVE-2025-21947? +

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix type confusion via race condition when using ipc_msg_send_request req->handle is allocated using ksmbd_acquire_id(&ipc_ida), based on ida_alloc. req->handle from ksmbd_ipc_login_request and FSCTL_PIPE_TRANSCEIVE ioctl can be same and it could lead to type confusion between messages, resulting in access to unexpected parts of memory after an incorrect delivery. ksmbd check type of ipc response but missing add continue to check next ipc reponse. It has a CVSS v3.1 base score of 8.1 (HIGH).

How severe is CVE-2025-21947? +

CVE-2025-21947 has a CVSS v3.1 score of 8.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-21947? +

CVE-2025-21947 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-2025-21947? +

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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