| Message ID | cc537bd6-837f-4c85-a37b-1a007e268310@stanley.mountain (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | drm/mediatek: Fix potential NULL dereference in mtk_crtc_destroy() | expand |
Il 12/09/24 10:44, Dan Carpenter ha scritto: > 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@linaro.org> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
diff --git a/drivers/gpu/drm/mediatek/mtk_crtc.c b/drivers/gpu/drm/mediatek/mtk_crtc.c index 175b00e5a253..c15013792583 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; }
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@linaro.org> --- drivers/gpu/drm/mediatek/mtk_crtc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)