From: Lee Jones <lee@kernel.org>
To: lee@kernel.org, Pavel Machek <pavel@kernel.org>,
John Lenz <lenz@cs.wisc.edu>,
Richard Purdie <rpurdie@openedhand.com>,
Jacek Anaszewski <jacek.anaszewski@gmail.com>,
Luis Henriques <lhenriques@suse.com>,
linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Subject: [PATCH 11/21] leds: class: Unlock led_access before unregistering device on error
Date: Wed, 21 Oct 2026 12:32:20 +0000 [thread overview]
Message-ID: <20261021123406.3163547-12-lee@kernel.org> (raw)
In-Reply-To: <20261021123406.3163547-1-lee@kernel.org>
In led_classdev_register_ext(), if led_add_brightness_hw_changed() fails
after device_create_with_groups() has exposed the LED sysfs attributes,
calling device_unregister() while holding led_cdev->led_access can
cause an AB-BA deadlock with a concurrent sysfs access that holds an
active kernfs reference and blocks on led_cdev->led_access.
Disable sysfs writes and release led_cdev->led_access before calling
device_unregister() on the error path.
Fixes: 6d71021ab3b0 ("leds: class: ensure workqueue is initialized before setting brightness")
Closes: https://sashiko.dev/#/bug/linux-400d8d29-9e78-4fb7-af37-b07c92bdf4df
Cc: stable@vger.kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>
---
drivers/leds/led-class.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 2a3040fa3c4b..c8529003dbe1 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -549,9 +549,10 @@ int led_classdev_register_ext(struct device *parent,
if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) {
ret = led_add_brightness_hw_changed(led_cdev);
if (ret) {
+ led_sysfs_disable(led_cdev);
+ mutex_unlock(&led_cdev->led_access);
device_unregister(led_cdev->dev);
led_cdev->dev = NULL;
- mutex_unlock(&led_cdev->led_access);
return ret;
}
}
--
2.56.0.218.g1ec904b173-goog
next prev parent reply other threads:[~2026-10-21 12:35 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-21 12:32 [PATCH 00/21] leds: Assorted bug fixes across core, flash, trigger, and drivers Lee Jones
2026-10-21 12:32 ` [PATCH 01/21] leds: lm3532: Propagate error from devm_regulator_get() Lee Jones
2026-10-21 12:32 ` [PATCH 02/21] leds: lm3532: Use dev_err_probe() when lm3532_parse_node() fails Lee Jones
2026-10-21 12:32 ` [PATCH 03/21] leds: trigger: netdev: Hold RTNL lock across hw_control_get_device() in activate Lee Jones
2026-10-21 12:32 ` [PATCH 04/21] leds: aw2013: Guard LED array index in aw2013_probe_dt() Lee Jones
2026-10-21 12:32 ` [PATCH 05/21] leds: pca955x: Take a reference on the child firmware node Lee Jones
2026-10-21 12:32 ` [PATCH 06/21] leds: lp50xx: Guard sub-LED count in lp50xx_probe_dt() Lee Jones
2026-10-21 12:32 ` [PATCH 07/21] leds: trigger: netdev: Serialise work cancellation and state updates Lee Jones
2026-10-21 12:32 ` [PATCH 08/21] leds: sgm3140: Replace powerdown timer with delayed work Lee Jones
2026-10-21 12:32 ` [PATCH 09/21] leds: sgm3140: Cancel powerdown work via devres after LED unregistration Lee Jones
2026-10-21 12:32 ` [PATCH 10/21] leds: class: Initialise trigger_lock before exposing sysfs attributes Lee Jones
2026-10-21 12:32 ` Lee Jones [this message]
2026-10-21 12:32 ` [PATCH 12/21] leds: aat1290: Retain child device_node reference for device lifetime Lee Jones
2026-10-21 12:32 ` [PATCH 13/21] leds: aat1290: Prevent out-of-bounds read in aat1290_brightness_to_intensity() Lee Jones
2026-10-21 12:32 ` [PATCH 14/21] leds: flash: Avoid divide-by-zero in led_clamp_align() Lee Jones
2026-10-21 12:32 ` [PATCH 15/21] leds: lm3532: Validate LED string indices in lm3532_parse_node() Lee Jones
2026-10-21 12:32 ` [PATCH 16/21] leds: lm3532: Clamp full-scale current to minimum bound Lee Jones
2026-10-21 12:32 ` [PATCH 17/21] leds: aat1290: Avoid leaking devres pinctrl handles on strobe source changes Lee Jones
2026-10-21 12:32 ` [PATCH 18/21] leds: aw2013: Unlock chip mutex before registering LEDs Lee Jones
2026-10-21 12:32 ` [PATCH 19/21] leds: is31fl32xx: Clamp channel current limit in is31fl3293_reset() Lee Jones
2026-10-21 12:32 ` [PATCH 20/21] leds: flash: Terminate sysfs_groups array with NULL Lee Jones
2026-10-21 12:32 ` [PATCH 21/21] leds: lm3692x: Use devm_mutex_init() to avoid premature mutex destruction Lee Jones
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