Linux LED subsystem development
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From: Arunachalam <arun07172003@gmail.com>
To: Lee Jones <lee@kernel.org>, Pavel Machek <pavel@kernel.org>
Cc: linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org,
	Arunachalam <arun07172003@gmail.com>
Subject: [PATCH 2/2] leds: cobalt-raq: Use devm_led_classdev_register() to fix use-after-unmap
Date: Sat, 25 Jul 2026 23:22:36 +0530	[thread overview]
Message-ID: <20260725175236.32015-1-arun07172003@gmail.com> (raw)
In-Reply-To: <20260725082003.F423C1F000E9@smtp.kernel.org>

The driver had no .remove callback, but registered its LEDs with the
unmanaged led_classdev_register() while the I/O mapping for led_port
was already managed via devres. If the driver was unbound, devres
would unmap led_port, but the LED classdevs would remain registered
with no matching teardown. A subsequent sysfs brightness write would
then dereference the now-unmapped led_port pointer.

Switch to devm_led_classdev_register() so LED registration and the
I/O mapping share the same devres lifetime and are torn down in the
correct order automatically.

Signed-off-by: Arunachalam <arun07172003@gmail.com>
---
 drivers/leds/leds-cobalt-raq.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/leds/leds-cobalt-raq.c b/drivers/leds/leds-cobalt-raq.c
index 5b5acaa8c..ecb64ca9d 100644
--- a/drivers/leds/leds-cobalt-raq.c
+++ b/drivers/leds/leds-cobalt-raq.c
@@ -76,19 +76,16 @@ static int cobalt_raq_led_probe(struct platform_device *pdev)
 	if (!led_port)
 		return -ENOMEM;
 
-	retval = led_classdev_register(&pdev->dev, &raq_power_off_led);
+	retval = devm_led_classdev_register(&pdev->dev, &raq_power_off_led);
 	if (retval)
 		goto err_null;
 
-	retval = led_classdev_register(&pdev->dev, &raq_web_led);
+	retval = devm_led_classdev_register(&pdev->dev, &raq_web_led);
 	if (retval)
-		goto err_unregister;
+		goto err_null;
 
 	return 0;
 
-err_unregister:
-	led_classdev_unregister(&raq_power_off_led);
-
 err_null:
 	led_port = NULL;
 
-- 
2.39.5


      reply	other threads:[~2026-07-25 17:52 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-25  8:13 [PATCH v3 1/4] leds: cobalt-raq: Add missing MODULE_DESCRIPTION Arunachalam
2026-07-25  8:13 ` [PATCH v3 2/4] leds: lp8788: Convert to dev_err_probe() Arunachalam
2026-07-25  8:21   ` sashiko-bot
2026-07-25  8:13 ` [PATCH v3 3/4] leds: menf21bmc: " Arunachalam
2026-07-25  8:19   ` sashiko-bot
2026-07-25 17:51     ` [PATCH 1/2] leds: menf21bmc: Use brightness_set_blocking instead of brightness_set Arunachalam
2026-07-25  8:13 ` [PATCH v3 4/4] leds: 88pm860x: Convert to dev_err_probe() Arunachalam
2026-07-25  8:19   ` sashiko-bot
2026-07-25  8:20 ` [PATCH v3 1/4] leds: cobalt-raq: Add missing MODULE_DESCRIPTION sashiko-bot
2026-07-25 17:52   ` Arunachalam [this message]

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