In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: Fix NULL sink dereference in USB4 bandwidth functions

allocate_usb4_bandwidth_for_stream() and allocate_usb4_bandwidth() both
use ASSERT(stream->sink) before dereferencing stream->sink->link. ASSERT
is compiled out in production builds, so a NULL stream->sink causes a
NULL pointer dereference.

link_set_dpms_off() already guards two earlier accesses to stream->sink
with explicit NULL checks, confirming that stream->sink can legitimately
be NULL. The subsequent call to deallocate_usb4_bandwidth() had no
equivalent guard.

Replace the ASSERT() calls with proper NULL checks that return false
early, and add a matching stream->sink guard at the call site in
link_set_dpms_off() consistent with the surrounding pattern.

v2: Keep the existing ASSERT() calls for diagnostics (to report
unexpected NULL sink), and add explicit NULL checks that return false
before dereferencing stream->sink. Also add a matching stream->sink
guard at the deallocation call site in link_set_dpms_off(). (Alex)

(cherry picked from commit 98029a0ce61feb52c563f65349dd9b25f672e355)
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 28 Oct 2026 14:30:00 +0000

Type Values Removed Values Added
First Time appeared Linux linux
Vendors & Products Linux linux

Wed, 28 Oct 2026 12:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-476

Wed, 28 Oct 2026 10:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix NULL sink dereference in USB4 bandwidth functions allocate_usb4_bandwidth_for_stream() and allocate_usb4_bandwidth() both use ASSERT(stream->sink) before dereferencing stream->sink->link. ASSERT is compiled out in production builds, so a NULL stream->sink causes a NULL pointer dereference. link_set_dpms_off() already guards two earlier accesses to stream->sink with explicit NULL checks, confirming that stream->sink can legitimately be NULL. The subsequent call to deallocate_usb4_bandwidth() had no equivalent guard. Replace the ASSERT() calls with proper NULL checks that return false early, and add a matching stream->sink guard at the call site in link_set_dpms_off() consistent with the surrounding pattern. v2: Keep the existing ASSERT() calls for diagnostics (to report unexpected NULL sink), and add explicit NULL checks that return false before dereferencing stream->sink. Also add a matching stream->sink guard at the deallocation call site in link_set_dpms_off(). (Alex) (cherry picked from commit 98029a0ce61feb52c563f65349dd9b25f672e355)
Title drm/amd/display: Fix NULL sink dereference in USB4 bandwidth functions
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-28T10:35:06.866Z

Reserved: 2026-09-25T10:25:14.396Z

Link: CVE-2026-99151

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-28T11:17:35.207

Modified: 2026-10-28T11:17:35.207

Link: CVE-2026-99151

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-28T14:15:18Z

Weaknesses