6.11-stable review patch. If anyone has any objections, please let me know.
------------------
From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
[ Upstream commit 4018651ba5c409034149f297d3dd3328b91561fd ]
In mtk_crtc_create(), if the call to mbox_request_channel() fails then we
set the "mtk_crtc->cmdq_client.chan" pointer to NULL. In that situation,
we do not call cmdq_pkt_create().
During the cleanup, we need to check if the "mtk_crtc->cmdq_client.chan"
is NULL first before calling cmdq_pkt_destroy(). Calling
cmdq_pkt_destroy() is unnecessary if we didn't call cmdq_pkt_create() and
it will result in a NULL pointer dereference.
Fixes: 7627122fd1c0 ("drm/mediatek: Add cmdq_handle in mtk_crtc")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Reviewed-by: CK Hu <ck.hu@xxxxxxxxxxxx>
Link: https://patchwork.kernel.org/project/dri-devel/patch/cc537bd6-837f-4c85-a37b-1a007e268310@stanley.mountain/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/mediatek/mtk_crtc.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_crtc.c b/drivers/gpu/drm/mediatek/mtk_crtc.c
index 4bee0328bdbee..e5d412b2d61b6 100644
--- a/drivers/gpu/drm/mediatek/mtk_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_crtc.c
@@ -127,9 +127,8 @@ static void mtk_crtc_destroy(struct drm_crtc *crtc)
mtk_mutex_put(mtk_crtc->mutex);
#if IS_REACHABLE(CONFIG_MTK_CMDQ)
- cmdq_pkt_destroy(&mtk_crtc->cmdq_client, &mtk_crtc->cmdq_handle);
-
if (mtk_crtc->cmdq_client.chan) {
+ cmdq_pkt_destroy(&mtk_crtc->cmdq_client, &mtk_crtc->cmdq_handle);
mbox_free_channel(mtk_crtc->cmdq_client.chan);
mtk_crtc->cmdq_client.chan = NULL;
}
--
2.43.0
