Bug 2513298 (CVE-2026-68256)

Summary: CVE-2026-68256 kernel: drm/amd/display: detect_link_and_local_sink: DP alt mode timeout path leaks prev_sink reference
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Priority: low    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
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Hardware: All   
OS: Linux   
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A flaw was found in the `drm/amd/display` component of the Linux kernel. This issue occurs in the `detect_link_and_local_sink` function, where a `prev_sink` reference is not properly released if the DisplayPort (DP) alt mode timeout path returns false. This missing cleanup can lead to a memory leak, potentially resulting in a Denial of Service (DoS) due to resource exhaustion.
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Description OSIDB Bzimport 2026-08-10 12:29:34 UTC
In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: detect_link_and_local_sink: DP alt mode timeout path leaks prev_sink reference

prev_sink is unconditionally retained via dc_sink_retain at function
  entry, but the DP alt mode timeout path inside SIGNAL_TYPE_DISPLAY_PORT
  returns false without releasing prev_sink. All other return paths in the
  function correctly call dc_sink_release(prev_sink), making this the only
  missing cleanup.

(cherry picked from commit 45510cf662dcf46b5d8926d454f338809f107b9d)