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

drm/mediatek: Fix a null pointer crash in mtk_drm_crtc_finish_page_flip

It's possible that mtk_crtc->event is NULL in
mtk_drm_crtc_finish_page_flip().

pending_needs_vblank value is set by mtk_crtc->event, but in
mtk_drm_crtc_atomic_flush(), it's is not guarded by the same
lock in mtk_drm_finish_page_flip(), thus a race condition happens.

Consider the following case:

CPU1 CPU2
step 1:
mtk_drm_crtc_atomic_begin()
mtk_crtc->event is not null,
step 1:
mtk_drm_crtc_atomic_flush:
mtk_drm_crtc_update_config(
!!mtk_crtc->event)
step 2:
mtk_crtc_ddp_irq ->
mtk_drm_finish_page_flip:
lock
mtk_crtc->event set to null,
pending_needs_vblank set to false
unlock
pending_needs_vblank set to true,

step 2:
mtk_crtc_ddp_irq ->
mtk_drm_finish_page_flip called again,
pending_needs_vblank is still true
//null pointer

Instead of guarding the entire mtk_drm_crtc_atomic_flush(), it's more
efficient to just check if mtk_crtc->event is null before use.
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-05-04T08:58:35.767Z

Reserved: 2024-02-19T14:20:24.185Z

Link: CVE-2024-26874

cve-icon Vulnrichment

Updated: 2024-08-02T00:21:04.219Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2024-04-17T11:15:09.670

Modified: 2024-11-21T09:03:16.010

Link: CVE-2024-26874

cve-icon Redhat

Severity : Low

Publid Date: 2024-04-17T00:00:00Z

Links: CVE-2024-26874 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-07-13T21:06:43Z