pinctrl: fix deadlock in create_pinctrl() when handling -EPROBE_DEFER

In create_pinctrl(), pinctrl_maps_mutex is acquired before calling add_setting(). If add_setting() returns -EPROBE_DEFER, create_pinctrl() calls pinctrl_free(). However, pinctrl_free() attempts to acquire pinctrl_maps_mutex, which is already held by create_pinctrl(), leading to a potential deadlock.

This patch resolves the issue by releasing pinctrl_maps_mutex before calling pinctrl_free(), preventing the deadlock.

This bug was discovered and resolved using Coverity Static Analysis Security Testing (SAST) by Synopsys, Inc.

---
only compile tested
v2: Updated the commit msg.

---
 drivers/pinctrl/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index cffeb869130d..f424a57f0013 100644
@@ -1106,8 +1106,8 @@ static struct pinctrl *create_pinctrl(struct device *dev,
 		 * an -EPROBE_DEFER later, as that is the worst case.
 		 */
 		if (ret == -EPROBE_DEFER) {
-			pinctrl_free(p, false);
 			mutex_unlock(&pinctrl_maps_mutex);
+			pinctrl_free(p, false);
 			return ERR_PTR(ret);
 		}
 	}

2.40.1

Looks like a real issue so patch applied for fixes.

Yours,
Linus Walleij