From: Anson Jacob <redacted>

[ Upstream commit 6a30a92997eee49554f72b462dce90abe54a496f ]

[Why]
dc_cursor_position do not initialise position.translate_by_source when
crtc or plane->state->fb is NULL. UBSAN caught this error in
dce110_set_cursor_position, as the value was garbage.

[How]
Initialise dc_cursor_position structure elements to 0 in handle_cursor_update
before calling get_cursor_position.

Tested-by: Daniel Wheeler <redacted>
Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1471
Reported-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Anson Jacob <redacted>
Reviewed-by: Aurabindo Jayamohanan Pillai <redacted>
Acked-by: Solomon Chiu <redacted>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 2626aacf492f..1aec841fda35 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -5372,10 +5372,6 @@ static int get_cursor_position(struct drm_plane *plane, struct drm_crtc *crtc,
 	int x, y;
 	int xorigin = 0, yorigin = 0;
 
-	position->enable = false;
-	position->x = 0;
-	position->y = 0;
-
 	if (!crtc || !plane->state->fb)
 		return 0;
 

@@ -5427,7 +5423,7 @@ static void handle_cursor_update(struct drm_plane *plane,
 	struct dm_crtc_state *crtc_state = crtc ? to_dm_crtc_state(crtc->state) : NULL;
 	struct amdgpu_crtc *amdgpu_crtc = to_amdgpu_crtc(crtc);
 	uint64_t address = afb ? afb->address : 0;
-	struct dc_cursor_position position;
+	struct dc_cursor_position position = {0};
 	struct dc_cursor_attributes attributes;
 	int ret;
 

-- 
2.30.2