From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792586098; b=yjZ2vgPbunSdUUJEoI9ICyPchk76ynmPHT/rBVJ17BaVADSEkFQJU4LOkKoH+imrFlVd I69pDeGoryhZdOk+QejvYHdbzM58HNpGI+zg19//tawE6G5+Y5+b2Oaadk/m1KxvJ8rEx ZwdZcsZaW004mFlYXACdvkwNWbyrC8mVvM2bXdI6WcpuZQAUOd/zT7sibhzpIUHw4Ge9M Vi2WTrvAAeVVQxcDnbpHrXk+whzZDtWs7V4Khbf33U9YEWzhRhWgP7PBNObd59VWUXyJF gsGHExtv7CGu9KRCJgit6G0x1pKzZvnk0T9HNAOrDMHhsO8Rwr6wxHPTqB6MOslPxUg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792586098; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=LpNJTSOvMtLLtZ7695vlyc9Z8uHqSLJQ+uBGS+day94=; b=5PPlgnXom5voNjT3buEVxxLKzr+njVSLgrdkdk3ZrUCpra09vkquYI9F4HohKGstLLdU B9QRfQPzd450Z5yxQNFsnYCT+vqgZcc3mC3Jpr1F8fE3IH2oRGirYzetgzPWe/Ac6bYmh 2+iqZEW16yW4+QmCXN5nARfClhBIf+lyXRgpaAAFjBZ25XfjsOBpFiYVmHejrQvAMlQuK TY9vdxeZ/3u8IFJt2pUpTV0H7M1VAGnl8BYVqSllYNK2b5eC/P6LkamPc0MRP9/RT3oP6 JoU5wF0CUkZA+DUivAL7+AI8sMP2AMTDfxdKcHeM3tt02lU7YyYpuE0weibEsC8qHsw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=G65XMEaj; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7C36D60A2613; Wed, 21 Oct 2026 12:34:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=G65XMEaj Received: by smtp.kernel.org (Postfix) with ESMTPSA id 696C91F000C4; Wed, 21 Oct 2026 12:34:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792586098; bh=LpNJTSOvMtLLtZ7695vlyc9Z8uHqSLJQ+uBGS+day94=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=G65XMEajKicms9TEsD6d8NacFfBhwfuf/e6yeIOta0kaI+cyU0RQr6nuUoM8Ni1yY UPTyPkE4Xl+rEZsacPTzfbFLmOA9MllVhBXzrohr0DyrwRORo22HoL5F3v6J+avLRE JTci4jkrpepqLALGhvtbtJ1767mP2EoZahNd2swNu3YsbkJ1d23fWtSlIBqqmsX3z8 9PEsIPaIkBv+Og4AwTCMy7JsfYyLtLS3ZYjaaz2zYTxmEjUz8/Ldgoprr/XPGyPjyB JWx2qFLq1Djgcx/Ki7DQ3sXiew4zCFD9jLbGuXW5oYQA4exCKpIQ/+1qqgiQunYLSH W9KlVV2EydpBg== From: Lee Jones To: lee@kernel.org, Pavel Machek , Ben Whitten , Oliver Jowett , Richard Purdie , Jacek Anaszewski , linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Subject: [PATCH 07/21] leds: trigger: netdev: Serialise work cancellation and state updates Date: Wed, 21 Oct 2026 12:32:16 +0000 Message-ID: <20261021123406.3163547-8-lee@kernel.org> X-Mailer: git-send-email 2.56.0.218.g1ec904b173-goog In-Reply-To: <20261021123406.3163547-1-lee@kernel.org> References: <20261021123406.3163547-1-lee@kernel.org> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit set_device_name() and netdev_trig_notify() cancel trigger_data->work before acquiring trigger_data->lock, whilst netdev_led_attr_store() and interval_store() cancel trigger_data->work, update trigger_data state, and call set_baseline_state() without holding trigger_data->lock at all. Because set_baseline_state() can re-arm trigger_data->work outside the lock, a concurrent notifier or sysfs store can re-schedule netdev_trig_work() after cancel_delayed_work_sync() has returned and whilst set_device_name() or netdev_trig_notify() is replacing or dropping trigger_data->net_dev, leading to a use-after-free in netdev_trig_work(). Move cancel_delayed_work_sync() inside trigger_data->lock in set_device_name() and netdev_trig_notify(), and hold trigger_data->lock across work cancellation, state updates, and set_baseline_state() in netdev_led_attr_store() and interval_store(). Fixes: 06f502f57d0d ("leds: trigger: Introduce a NETDEV trigger") Closes: https://sashiko.dev/#/bug/linux-b2b6c3bb-8017-4623-94d4-2999efa6a663 Cc: stable@vger.kernel.org Signed-off-by: Lee Jones --- drivers/leds/trigger/ledtrig-netdev.c | 35 +++++++++++++++++++-------- 1 file changed, 25 insertions(+), 10 deletions(-) diff --git a/drivers/leds/trigger/ledtrig-netdev.c b/drivers/leds/trigger/ledtrig-netdev.c index d69031bbd2b8..9fa56ac523c7 100644 --- a/drivers/leds/trigger/ledtrig-netdev.c +++ b/drivers/leds/trigger/ledtrig-netdev.c @@ -284,8 +284,6 @@ static int set_device_name(struct led_netdev_data *trigger_data, if (size >= IFNAMSIZ) return -EINVAL; - cancel_delayed_work_sync(&trigger_data->work); - memcpy(device_name, name, size); device_name[size] = 0; if (size > 0 && device_name[size - 1] == '\n') @@ -301,6 +299,8 @@ static int set_device_name(struct led_netdev_data *trigger_data, } mutex_lock(&trigger_data->lock); + cancel_delayed_work_sync(&trigger_data->work); + dev_put(trigger_data->net_dev); trigger_data->net_dev = new_dev; strscpy(trigger_data->device_name, device_name); @@ -384,7 +384,7 @@ static ssize_t netdev_led_attr_store(struct device *dev, const char *buf, { struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev); struct led_classdev *led_cdev = trigger_data->led_cdev; - unsigned long state, mode = trigger_data->mode; + unsigned long state, mode; int ret; int bit; @@ -416,6 +416,9 @@ static ssize_t netdev_led_attr_store(struct device *dev, const char *buf, return -EINVAL; } + mutex_lock(&trigger_data->lock); + + mode = trigger_data->mode; assign_bit(bit, &mode, state); if (test_bit(TRIGGER_NETDEV_LINK, &mode) && @@ -428,8 +431,10 @@ static ssize_t netdev_led_attr_store(struct device *dev, const char *buf, test_bit(TRIGGER_NETDEV_LINK_25000, &mode) || test_bit(TRIGGER_NETDEV_LINK_40000, &mode) || test_bit(TRIGGER_NETDEV_LINK_50000, &mode) || - test_bit(TRIGGER_NETDEV_LINK_100000, &mode))) + test_bit(TRIGGER_NETDEV_LINK_100000, &mode))) { + mutex_unlock(&trigger_data->lock); return -EINVAL; + } cancel_delayed_work_sync(&trigger_data->work); @@ -437,11 +442,15 @@ static ssize_t netdev_led_attr_store(struct device *dev, const char *buf, trigger_data->hw_control = can_hw_control(trigger_data); if (!led_cdev->brightness_set && !led_cdev->brightness_set_blocking && - !trigger_data->hw_control) + !trigger_data->hw_control) { + mutex_unlock(&trigger_data->lock); return -EOPNOTSUPP; + } set_baseline_state(trigger_data); + mutex_unlock(&trigger_data->lock); + return size; } @@ -493,13 +502,17 @@ static ssize_t interval_store(struct device *dev, unsigned long value; int ret; - if (trigger_data->hw_control) - return -EINVAL; - ret = kstrtoul(buf, 0, &value); if (ret) return ret; + mutex_lock(&trigger_data->lock); + + if (trigger_data->hw_control) { + mutex_unlock(&trigger_data->lock); + return -EINVAL; + } + /* impose some basic bounds on the timer interval */ if (value >= 5 && value <= 10000) { cancel_delayed_work_sync(&trigger_data->work); @@ -508,6 +521,8 @@ static ssize_t interval_store(struct device *dev, set_baseline_state(trigger_data); /* resets timer */ } + mutex_unlock(&trigger_data->lock); + return size; } @@ -628,10 +643,10 @@ static int netdev_trig_notify(struct notifier_block *nb, (evt == NETDEV_REGISTER && !strcmp(dev->name, trigger_data->device_name)))) return NOTIFY_DONE; - cancel_delayed_work_sync(&trigger_data->work); - mutex_lock(&trigger_data->lock); + cancel_delayed_work_sync(&trigger_data->work); + trigger_data->carrier_link_up = false; trigger_data->link_speed = SPEED_UNKNOWN; trigger_data->duplex = DUPLEX_UNKNOWN; -- 2.56.0.218.g1ec904b173-goog