usb: typec: ucsi: Clear PPM capability data in ucsi_init() error path

From: Mayank Rana <[email protected]>

If ucsi_init() fails for some reason (e.g. ucsi_register_port() fails or general communication failure to the PPM), particularly at any point after the GET_CAPABILITY command had been issued, this results in unwinding the initialization and returning an error. However the ucsi structure's ucsi_capability member retains its current value, including likely a non-zero num_connectors. And because ucsi_init() itself is done in a workqueue a UCSI interface driver will be unaware that it failed and may think the ucsi_register() call was completely successful. Later, if ucsi_unregister() is called, due to this stale ucsi->cap value it would try to access the items in the ucsi->connector array which might not be in a proper state or not even allocated at all and results in NULL or invalid pointer dereference.

Fix this by clearing the ucsi->cap value to 0 during the error path of ucsi_init() in order to prevent a later ucsi_unregister() from entering the connector cleanup loop.

Fixes c1b0bc2dabfa ("usb: typec: Add support for UCSI interface")

Cc [email protected]

Signed-off-by Mayank Rana <[email protected]>

Signed-off-by Jack Pham <[email protected]>

---
 drivers/usb/typec/ucsi/ucsi.c | 1 +
 1 file changed, 1 insertion(+)

drivers/usb/typec/ucsi/ucsi.c +1 -0

index b433169ef6fa..b7d104c80d85 100644
@@ -1253,6 +1253,7 @@ static int ucsi_init(struct ucsi *ucsi)
 	}
 
 err_reset:
+	memset(&ucsi->cap, 0, sizeof(ucsi->cap));
 	ucsi_reset_ppm(ucsi);
 err:
 	return ret;

Signature · 1 line

2.24.0