Description
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.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
119f5173628aa7a0c3cf9db83460d40709e8241d to < accdac6b71d5a2b84040c3d2234f53a60edc398eaffected119f5173628aa7a0c3cf9db83460d40709e8241d to < dfde84cc6c589f2a9f820f12426d97365670b731affected119f5173628aa7a0c3cf9db83460d40709e8241d to < 4688be96d20ffa49d2186523ee84f475f316fd49affected119f5173628aa7a0c3cf9db83460d40709e8241d to < 9beec711a17245b853d64488fd5b739031612340affected119f5173628aa7a0c3cf9db83460d40709e8241d to < d2bd30c710475b2e29288827d2c91f9e6e2b91d7affected119f5173628aa7a0c3cf9db83460d40709e8241d to < a3dd12b64ae8373a41a216a0b621df224210860aaffected119f5173628aa7a0c3cf9db83460d40709e8241d to < 9acee29a38b4d4b70f1f583e5ef9a245db4db710affected119f5173628aa7a0c3cf9db83460d40709e8241d to < 3fc88b246a2fc16014e374040fc15af1d3752535affected119f5173628aa7a0c3cf9db83460d40709e8241d to < c958e86e9cc1b48cac004a6e245154dfba8e163baffected
Linux Linux
Default version status: affected
4.7affected0 to < 4.7unaffected4.19.311 to ≤ 4.19.*unaffected5.4.273 to ≤ 5.4.*unaffected5.10.214 to ≤ 5.10.*unaffected5.15.153 to ≤ 5.15.*unaffected6.1.83 to ≤ 6.1.*unaffected6.6.23 to ≤ 6.6.*unaffected6.7.11 to ≤ 6.7.*unaffected6.8.2 to ≤ 6.8.*unaffected6.9 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/accdac6b71d5a2b84040c3d2234f53a60edc398e ↗
- https://git.kernel.org/stable/c/dfde84cc6c589f2a9f820f12426d97365670b731 ↗
- https://git.kernel.org/stable/c/4688be96d20ffa49d2186523ee84f475f316fd49 ↗
- https://git.kernel.org/stable/c/9beec711a17245b853d64488fd5b739031612340 ↗
- https://git.kernel.org/stable/c/d2bd30c710475b2e29288827d2c91f9e6e2b91d7 ↗
- https://git.kernel.org/stable/c/a3dd12b64ae8373a41a216a0b621df224210860a ↗
- https://git.kernel.org/stable/c/9acee29a38b4d4b70f1f583e5ef9a245db4db710 ↗
- https://git.kernel.org/stable/c/3fc88b246a2fc16014e374040fc15af1d3752535 ↗
- https://git.kernel.org/stable/c/c958e86e9cc1b48cac004a6e245154dfba8e163b ↗
- https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html ↗
- https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html ↗