Bug 2422702 (CVE-2025-40354)

Summary: CVE-2025-40354 kernel: Linux kernel: Privilege escalation in AMD display driver
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's AMD display (drm/amd/display) driver. This vulnerability involves an incorrect array size calculation and a null pointer dereference during hardware initialization. A local attacker with low privileges could exploit these issues to cause a system crash, leading to a denial of service. More critically, this flaw could potentially be leveraged for privilege escalation, allowing the attacker to gain unauthorized higher access to the system.
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Description OSIDB Bzimport 2025-12-16 14:04:56 UTC 
In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: increase max link count and fix link->enc NULL pointer access

[why]
1.) dc->links[MAX_LINKS] array size smaller than actual requested.
max_connector + max_dpia + 4 virtual = 14.
increase from 12 to 14.

2.) hw_init() access null LINK_ENC for dpia non display_endpoint.

(cherry picked from commit d7f5a61e1b04ed87b008c8d327649d184dc5bb45)
Comment 1 Alexander B 2025-12-17 01:54:37 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025121637-CVE-2025-40354-b9bd@gregkh/T