Re: [PATCH] drm/mediatek: Fix potential NULL dereference in mtk_crtc_destroy()

From: AngeloGioacchino Del Regno
Date: Thu Sep 12 2024 - 05:05:23 EST


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@xxxxxxxxxx>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>