CVE-2025-39675: debian linux Null Dereference — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Add null pointer check in mod_hdcp_hdcp1_create_session() The function mod_hdcp_hdcp1_create_session() calls the function get_first_active_display(), but does not check its return value. The return value is a null pointer if the display list is empty. This will lead to a null pointer dereference. Add a null pointer check for get_first_active_display() and return MOD_HDCP_STATUS_DISPLAY_NOT_FOUND if the function return null. This is similar to the commit c3e9826a2202 ("drm/amd/display: Add null pointer check for get_first_active_display()"). (cherry picked from commit 5e43eb3cd731649c4f8b9134f857be62a416c893)

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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	5.8 — 5.15.190
linux	linux_kernel	5.16 — 6.1.149
linux	linux_kernel	6.2 — 6.6.103
linux	linux_kernel	6.7 — 6.12.44
linux	linux_kernel	6.13 — 6.16.4
linux	linux_kernel	All
linux	linux_kernel	All
debian	debian_linux	All

References

Advisories & Patches

https://git.kernel.org/stable/c/2af45aadb7b5d3852c76e2d1e985289ada6f48bf https://git.kernel.org/stable/c/2ee86b764c54e0d6a5464fb023b630fdf20869cd https://git.kernel.org/stable/c/7a2ca2ea64b1b63c8baa94a8f5deb70b2248d119 https://git.kernel.org/stable/c/857b8387a9777e42b36e0400be99b54c251eaf9a https://git.kernel.org/stable/c/97fc94c5fd3c6ac5a13e457d38ee247737b8c4bd https://git.kernel.org/stable/c/ee0373b20bb67b1f00a1b25ccd24c8ac996b6446

Other References

https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html https://cert-portal.siemens.com/productcert/html/ssa-032379.html

Frequently Asked Questions

What is CVE-2025-39675? +

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Add null pointer check in mod_hdcp_hdcp1_create_session() The function mod_hdcp_hdcp1_create_session() calls the function get_first_active_display(), but does not check its return value. The return value is a null pointer if the display list is empty. This will lead to a null pointer dereference. Add a null pointer check for get_first_active_display() and return MOD_HDCP_STATUS_DISPLAY_NOT_FOUND if the function return null. This is similar to the commit c3e9826a2202 ("drm/amd/display: Add null pointer check for get_first_active_display()"). (cherry picked from commit 5e43eb3cd731649c4f8b9134f857be62a416c893) It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2025-39675? +

CVE-2025-39675 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-2025-39675? +

CVE-2025-39675 affects products from debian, linux, specifically: debian_linux, linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-39675? +

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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