| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2024-26874: drm/mediatek: Fix a null pointer crash in mtk_drm_crtc_finish_page_flip |
| |
| 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. |
| |
| The Linux kernel CVE team has assigned CVE-2024-26874 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.7 with commit 119f5173628aa7a0c3cf9db83460d40709e8241d and fixed in 4.19.311 with commit accdac6b71d5a2b84040c3d2234f53a60edc398e |
| Issue introduced in 4.7 with commit 119f5173628aa7a0c3cf9db83460d40709e8241d and fixed in 5.4.273 with commit dfde84cc6c589f2a9f820f12426d97365670b731 |
| Issue introduced in 4.7 with commit 119f5173628aa7a0c3cf9db83460d40709e8241d and fixed in 5.10.214 with commit 4688be96d20ffa49d2186523ee84f475f316fd49 |
| Issue introduced in 4.7 with commit 119f5173628aa7a0c3cf9db83460d40709e8241d and fixed in 5.15.153 with commit 9beec711a17245b853d64488fd5b739031612340 |
| Issue introduced in 4.7 with commit 119f5173628aa7a0c3cf9db83460d40709e8241d and fixed in 6.1.83 with commit d2bd30c710475b2e29288827d2c91f9e6e2b91d7 |
| Issue introduced in 4.7 with commit 119f5173628aa7a0c3cf9db83460d40709e8241d and fixed in 6.6.23 with commit a3dd12b64ae8373a41a216a0b621df224210860a |
| Issue introduced in 4.7 with commit 119f5173628aa7a0c3cf9db83460d40709e8241d and fixed in 6.7.11 with commit 9acee29a38b4d4b70f1f583e5ef9a245db4db710 |
| Issue introduced in 4.7 with commit 119f5173628aa7a0c3cf9db83460d40709e8241d and fixed in 6.8.2 with commit 3fc88b246a2fc16014e374040fc15af1d3752535 |
| Issue introduced in 4.7 with commit 119f5173628aa7a0c3cf9db83460d40709e8241d and fixed in 6.9 with commit c958e86e9cc1b48cac004a6e245154dfba8e163b |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2024-26874 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| drivers/gpu/drm/mediatek/mtk_drm_crtc.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| 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 |
