linux-kernel - [PATCH 2/4] gpio: shared: check if a reference is populated before cleaning its resources

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Message-Id: <20251206-gpio-shared-teardown-fixes-v1-2-35ac458cfce1@oss.qualcomm.com>
Date: Sat, 06 Dec 2025 12:53:54 +0100
From: Bartosz Golaszewski <bartosz.golaszewski@....qualcomm.com>
To: Linus Walleij <linusw@...nel.org>, Bartosz Golaszewski <brgl@...nel.org>
Cc: Linus Walleij <linus.walleij@...aro.org>, linux-gpio@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Bartosz Golaszewski <bartosz.golaszewski@....qualcomm.com>
Subject: [PATCH 2/4] gpio: shared: check if a reference is populated before
 cleaning its resources

It's possible that not all proxy entries will be set up when the device
gets removed so check if they are before trying to dereference members
which are still NULL. This can happen if some consumers never requested
their shared GPIOs.

Fixes: a060b8c511ab ("gpiolib: implement low-level, shared GPIO support")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@....qualcomm.com>
---
 drivers/gpio/gpiolib-shared.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/gpio/gpiolib-shared.c b/drivers/gpio/gpiolib-shared.c
index 17da15c1075f97f4ebed969b38197ac155141406..4084a28a953a7c9f4b04cbf867b05a1a74b557ca 100644
--- a/drivers/gpio/gpiolib-shared.c
+++ b/drivers/gpio/gpiolib-shared.c
@@ -491,10 +491,13 @@ void gpio_device_teardown_shared(struct gpio_device *gdev)
 			continue;
 
 		list_for_each_entry(ref, &entry->refs, list) {
-			gpiod_remove_lookup_table(ref->lookup);
-			kfree(ref->lookup->table[0].key);
-			kfree(ref->lookup);
-			ref->lookup = NULL;
+			if (ref->lookup) {
+				gpiod_remove_lookup_table(ref->lookup);
+				kfree(ref->lookup->table[0].key);
+				kfree(ref->lookup);
+				ref->lookup = NULL;
+			}
+
 			gpio_shared_remove_adev(&ref->adev);
 		}
 	}

-- 
2.51.0