# \[PATCH\] Input: psmouse - fix psmouse detect function is a NULL pointer

- From: Qiang Ma \<hidden\>
- Date: 2021-05-19 03:28:09 
- List: linux-input
- Page: https://ratatoskr.run/linux-input/2021/05/1382789
- Thread: https://ratatoskr.run/linux-input/2021/05/1382789/t.md

```text
Add a check for psmouse_do_detect(), when the detect is NULL pointer,
returning false, avoiding this possible NULL pointer exception.

Signed-off-by: Qiang Ma <redacted>
---
 drivers/input/mouse/psmouse-base.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
index 0b4a3039f312..86b095728587 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -1006,6 +1006,9 @@ static bool psmouse_do_detect(int (*detect)(struct psmouse *, bool),
 	if (set_properties)
 		psmouse_apply_defaults(psmouse);
 
+	if (!detect)
+		return false;
+
 	return detect(psmouse, set_properties) == 0;
 }
 
-- 
2.20.1



```