platform/chrome: cros_ec_typec: Fix remove partner logic

The cros_unregister_ports() function can be called in situations where
the partner has not been registered yet, and so its related data
structures would not have been initialized. Calling
cros_typec_remove_partner() in such a situation can lead to null pointer
dereferences. So, only call cros_typec_remove_partner() if there is a
valid registered partner pointer.

Signed-off-by: Prashant Malani <pmalani@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Link: https://lore.kernel.org/r/20201029222738.482366-3-pmalani@chromium.org

diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
index 49083e2..2665d81 100644 (file)
--- a/drivers/platform/chrome/cros_ec_typec.c
+++ b/drivers/platform/chrome/cros_ec_typec.c
@@ -190,7 +190,10 @@ static void cros_unregister_ports(struct cros_typec_data *typec)
        for (i = 0; i < typec->num_ports; i++) {
                if (!typec->ports[i])
                        continue;
-               cros_typec_remove_partner(typec, i);
+
+               if (typec->ports[i]->partner)
+                       cros_typec_remove_partner(typec, i);
+
                usb_role_switch_put(typec->ports[i]->role_sw);
                typec_switch_put(typec->ports[i]->ori_sw);
                typec_mux_put(typec->ports[i]->mux);