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

PATCH Superseded Hagar Hemdan 1 participant 1 message Jun 4, 2024

Subsystems (2)

v1 of 2 Superseded Latest is v2 →

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PATCH 1/1 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.

Fixes 42fed7ba44e4 ("pinctrl: move subsystem mutex to pinctrl_dev struct")

---
Only compile-tested.

---
 drivers/pinctrl/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/pinctrl/core.c +1 -1
index ee56856cb80c..29d9ef535dbe 100644
@@ -1102,8 +1102,8 @@ 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);
 		}
 	}
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2.40.1