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.

Fixes: 42fed7b ("pinctrl: move subsystem mutex to pinctrl_dev struct")
Suggested-by: Maximilian Heyne <[email protected]>
Signed-off-by: Hagar Hemdan <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Linus Walleij <[email protected]>

Author: hagarhem

drivers/pinctrl/core.c

@@ -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);
 		}
 	}