Commit f6c73e71 authored by Laurent Pinchart's avatar Laurent Pinchart Committed by Tomi Valkeinen
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drm: rcar-du: Fix crash when no CMM is available 



Commit 3bce3fdd ("drm: rcar-du: Don't leak device_link to CMM")
refactored CMM handling, and introduced an incorrect test for CMM
availability. When no CMM is present, the rcrtc->cmm field is NULL,
testing rcrtc->cmm->dev causes a NULL pointer dereference. This slipped
through testing as all tests were run with the CMM present.

Fix this issue by correctly testing for rcrtc->cmm.

Fixes: 3bce3fdd ("drm: rcar-du: Don't leak device_link to CMM")
Reported-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Closes: https://lore.kernel.org/dri-devel/CAMuHMdXomz9GFDqkBjGX9Sda_GLccPcrihvFbOz0GAitDVNTbw@mail.gmail.com


Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260408124205.1962448-1-laurent.pinchart+renesas@ideasonboard.com


Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ideasonboard.com>
(cherry picked from commit 3e9a1da270ddff449b1ad9eadc958f43bc204bd2)
Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ideasonboard.com>
parent dc6d5195

drivers/gpu/drm/renesas/rcar-du/rcar_du_crtc.c

+3 −3
Original line number Diff line number Diff line
@@ -513,7 +513,7 @@ static void rcar_du_cmm_setup(struct drm_crtc *crtc) 
	struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc);

	struct rcar_cmm_config cmm_config = {};



	if (!rcrtc->cmm->dev)

	if (!rcrtc->cmm)

		return;



	if (drm_lut)
@@ -667,7 +667,7 @@ static void rcar_du_crtc_stop(struct rcar_du_crtc *rcrtc) 
	if (rcar_du_has(rcrtc->dev, RCAR_DU_FEATURE_VSP1_SOURCE))

		rcar_du_vsp_disable(rcrtc);



	if (rcrtc->cmm->dev)

	if (rcrtc->cmm)

		rcar_cmm_disable(rcrtc->cmm->dev);



	/*
@@ -726,7 +726,7 @@ static void rcar_du_crtc_atomic_enable(struct drm_crtc *crtc, 
	struct rcar_du_crtc_state *rstate = to_rcar_crtc_state(crtc->state);

	struct rcar_du_device *rcdu = rcrtc->dev;



	if (rcrtc->cmm->dev)

	if (rcrtc->cmm)

		rcar_cmm_enable(rcrtc->cmm->dev);

	rcar_du_crtc_get(rcrtc);