[PATCH 6.18 153/752] drm/panel: Fix a possible null-pointer dereference in jdi_panel_dsi_remove()

Sasha Levin
2026-02-28T17:50:17Z

From: Tuo Li <islituo@gmail.com>

[ Upstream commit 95eed73b871111123a8b1d31cb1fce7e902e49ea ]

In jdi_panel_dsi_remove(), jdi is explicitly checked, indicating that it
may be NULL:

if (!jdi)
mipi_dsi_detach(dsi);

However, when jdi is NULL, the function does not return and continues by
calling jdi_panel_disable():

err = jdi_panel_disable(&jdi->base);

Inside jdi_panel_disable(), jdi is dereferenced unconditionally, which can
lead to a NULL-pointer dereference:

struct jdi_panel *jdi = to_panel_jdi(panel);
backlight_disable(jdi->backlight);

To prevent such a potential NULL-pointer dereference, return early from
jdi_panel_dsi_remove() when jdi is NULL.

Signed-off-by: Tuo Li <islituo@gmail.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20251218120955.11185-1-islituo@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/panel/panel-jdi-lpm102a188a.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panel/panel-jdi-lpm102a188a.c b/drivers/gpu/drm/panel/panel-jdi-lpm102a188a.c
index 23462065d726b..ea975170fafff 100644
--- a/drivers/gpu/drm/panel/panel-jdi-lpm102a188a.c
+++ b/drivers/gpu/drm/panel/panel-jdi-lpm102a188a.c
@@ -434,8 +434,10 @@ static void jdi_panel_dsi_remove(struct mipi_dsi_device *dsi)
int err;

/* only detach from host for the DSI-LINK2 interface */
- if (!jdi)
+ if (!jdi) {
mipi_dsi_detach(dsi);
+ return;
+ }

err = jdi_panel_disable(&jdi->base);
if (err < 0)
--
2.51.0