From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EDCAD42BE93; Sat, 12 Sep 2026 10:15:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789208155; cv=none; b=jNJhqJ2OGexoD9+Ca/dReI/kXykys9I9GvUUVyxSfiltedet2/7vVapokG4L4ICsXpwuAwgrokdvG01v1VmijO9GHLEOahY2xpPAs8W2KwUokq7VZ6FRcBChxZ7q14yLbN8KTrt2WPzGIqTxIMM3QG8JDpSsaqRe8ggA2302kAs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789208155; c=relaxed/simple; bh=bLGdTBY8FgYK5ZDRYmyPbaQR1aG/EA7I2QpVE1k7NJE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BuE5SHs0kNwaTJZhGQRO5gAYkP3zZe8tT14WikQyA8lLpUzaVkyaC6bglzUM8IZErSX8UKlMtqJPcjve7PRpr7ouM0ZvycwwkNdWuHrZVO8Jf1qpZBoIMAzmRG1hFVlfv+y6VG21QdhtbaL1i4tFlANhBUNyItAB93D5wv4Mh20= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=wWIPGjBU; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="wWIPGjBU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AE7B41F000FF; Sat, 12 Sep 2026 10:15:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789208153; bh=LdDhBdfg89AQXOpRG5ND7tnFDkx2P/HKSBb+/qPN6/I=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=wWIPGjBUZ1hlLCXy5i0wvmsLjCoZmbLk1wK9fQCSu/LFjMxPNDJBQHB5mQzU/3HtH 60YK/H+qaSeTfSjhS25M5rOrzr1U3is8LVM0MliUbIP2gjGvW6X1ubqCwdxz9VGGgi xBY5wQ5SlHUIgGVeokJKtHfZAp7RVZCWFuumLG0k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Cosmo Chou , Bartosz Golaszewski , Lee Jones , Sasha Levin Subject: [PATCH 6.18 0561/1518] leds: pca9532: Fix phantom device registration on missing hardware Date: Sat, 12 Sep 2026 08:45:30 +0200 Message-ID: <20260912065636.125981788@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065623.398859879@linuxfoundation.org> References: <20260912065623.398859879@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Cosmo Chou [ Upstream commit 8d6b6c05b8e33d11e3fb3203309385e1a9cceecd ] The initial PWM and PSC register writes in pca9532_configure() do not check the return values of i2c_smbus_write_byte_data(). If the I2C device is physically absent from the bus, the write fails with -ENXIO. However, the driver ignores this error and allows probe() to complete successfully. This results in the registration of phantom LED class devices and gpiochips backed by non-existent hardware. Subsequent GPIO reads from these phantom chips return bogus values (due to -ENXIO being truncated to an unsigned char in pca9532_gpio_get_value()), silently corrupting hardware state tracking in userspace. Propagate the I2C write failures back to probe() so the driver core can gracefully abort binding and release devres-managed resources. Fixes: e14fa82439d3 ("leds: Add pca9532 led driver") Signed-off-by: Cosmo Chou Reviewed-by: Bartosz Golaszewski Link: https://patch.msgid.link/20260715080747.1638097-1-chou.cosmo@gmail.com Signed-off-by: Lee Jones Signed-off-by: Sasha Levin --- drivers/leds/leds-pca9532.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/leds/leds-pca9532.c b/drivers/leds/leds-pca9532.c index 80bf94e699d41..af141dec4b927 100644 --- a/drivers/leds/leds-pca9532.c +++ b/drivers/leds/leds-pca9532.c @@ -395,10 +395,14 @@ static int pca9532_configure(struct i2c_client *client, for (i = 0; i < 2; i++) { data->pwm[i] = pdata->pwm[i]; data->psc[i] = pdata->psc[i]; - i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(maxleds, i), - data->pwm[i]); - i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(maxleds, i), - data->psc[i]); + err = i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(maxleds, i), + data->pwm[i]); + if (err < 0) + return err; + err = i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(maxleds, i), + data->psc[i]); + if (err < 0) + return err; } data->hw_blink = true; -- 2.53.0