CVE-2025-21775: linux kernel Null Dereference — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: can: ctucanfd: handle skb allocation failure If skb allocation fails, the pointer to struct can_frame is NULL. This is actually handled everywhere inside ctucan_err_interrupt() except for the only place. Add the missed NULL check. Found by Linux Verification Center (linuxtesting.org) with SVACE static analysis tool.

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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

Weakness Type (CWE)

CWE-476 CWE-476

Affected Products

Vendor	Product	Versions
linux	linux_kernel	5.19 — 6.1.129
linux	linux_kernel	6.2 — 6.6.79
linux	linux_kernel	6.7 — 6.12.16
linux	linux_kernel	6.13 — 6.13.4
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/84b9ac59978a6a4e0812d1c938fad97306272cef https://git.kernel.org/stable/c/9bd24927e3eeb85642c7baa3b28be8bea6c2a078 https://git.kernel.org/stable/c/b0e592dd46a0a952b41c3bf6c963afdd6a42b526 https://git.kernel.org/stable/c/e505b83b9ee6aa0ae2f4395f573a66579ae403fb https://git.kernel.org/stable/c/e7e2e2318b1f085044126ba553a4e619842fc36d

Other References

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

Frequently Asked Questions

What is CVE-2025-21775? +

In the Linux kernel, the following vulnerability has been resolved: can: ctucanfd: handle skb allocation failure If skb allocation fails, the pointer to struct can_frame is NULL. This is actually handled everywhere inside ctucan_err_interrupt() except for the only place. Add the missed NULL check. Found by Linux Verification Center (linuxtesting.org) with SVACE static analysis tool. It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2025-21775? +

CVE-2025-21775 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-2025-21775? +

CVE-2025-21775 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-2025-21775? +

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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