From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 EB0901F7089; Tue, 21 Jan 2025 17:58:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737482330; cv=none; b=HJktsY6ukqyJxFyjTaHhV0QKZoB7ijWNgXTFUuLDt6A60lZJzbrvihLxmo7vSMH5XeLQTcDQyAbSGqNm6hiljcVoQavi7yfGi4+sdXy5zomcbvF4QzYME4Fvih0G5HqbhR4f1XLJQ6GrKbznTHz0xruUwAdoGbYvss8+EUtgLPQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737482330; c=relaxed/simple; bh=tqWNI3YGsPp7axxVsS5R2aIA1j6yTTl9KJSbVom3uJY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=kY3wbAgl3N2WaVW/kiK7ATqWry9UAqbw5A4FH1hYclBIfv36CnkhXlxYsJxhX/2OQSm8HW1FgQR+uaM8rYxwG49kE16ush4A4Aeq/caRE9IeVl9ivMf+ELygKa516vf9/KIi9LLXQrQ2nctNA/FZJKPuNRrRco0w32kibavYyPk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=bLOX18ef; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="bLOX18ef" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1CEBCC4CEE0; Tue, 21 Jan 2025 17:58:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1737482329; bh=tqWNI3YGsPp7axxVsS5R2aIA1j6yTTl9KJSbVom3uJY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bLOX18efM4AlHSHAJXGSVoVfbkHCc1rJJZgFCniV1oLNEmzPj1fRmIzNDO4yQGTRt Cp2FBPJ6bXB/b/jt89PGm41lP/KQ9GbJUMOoj6uY4vzQWg4KwxKv849jC+ugPXhbYf /looroemNV88PJn/jrgLSD1HTxGpJ1THruriJNgY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chenyuan Yang , Hans de Goede , =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= , Sasha Levin Subject: [PATCH 6.12 040/122] platform/x86: dell-uart-backlight: fix serdev race Date: Tue, 21 Jan 2025 18:51:28 +0100 Message-ID: <20250121174534.528129518@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250121174532.991109301@linuxfoundation.org> References: <20250121174532.991109301@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chenyuan Yang [ Upstream commit 1b2128aa2d45ab20b22548dcf4b48906298ca7fd ] The dell_uart_bl_serdev_probe() function calls devm_serdev_device_open() before setting the client ops via serdev_device_set_client_ops(). This ordering can trigger a NULL pointer dereference in the serdev controller's receive_buf handler, as it assumes serdev->ops is valid when SERPORT_ACTIVE is set. This is similar to the issue fixed in commit 5e700b384ec1 ("platform/chrome: cros_ec_uart: properly fix race condition") where devm_serdev_device_open() was called before fully initializing the device. Fix the race by ensuring client ops are set before enabling the port via devm_serdev_device_open(). Note, serdev_device_set_baudrate() and serdev_device_set_flow_control() calls should be after the devm_serdev_device_open() call. Fixes: 484bae9e4d6a ("platform/x86: Add new Dell UART backlight driver") Signed-off-by: Chenyuan Yang Reviewed-by: Hans de Goede Link: https://lore.kernel.org/r/20250111180118.2274516-1-chenyuan0y@gmail.com Reviewed-by: Ilpo Järvinen Signed-off-by: Ilpo Järvinen Signed-off-by: Sasha Levin --- drivers/platform/x86/dell/dell-uart-backlight.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/platform/x86/dell/dell-uart-backlight.c b/drivers/platform/x86/dell/dell-uart-backlight.c index 3995f90add456..c45bc332af7a0 100644 --- a/drivers/platform/x86/dell/dell-uart-backlight.c +++ b/drivers/platform/x86/dell/dell-uart-backlight.c @@ -283,6 +283,9 @@ static int dell_uart_bl_serdev_probe(struct serdev_device *serdev) init_waitqueue_head(&dell_bl->wait_queue); dell_bl->dev = dev; + serdev_device_set_drvdata(serdev, dell_bl); + serdev_device_set_client_ops(serdev, &dell_uart_bl_serdev_ops); + ret = devm_serdev_device_open(dev, serdev); if (ret) return dev_err_probe(dev, ret, "opening UART device\n"); @@ -290,8 +293,6 @@ static int dell_uart_bl_serdev_probe(struct serdev_device *serdev) /* 9600 bps, no flow control, these are the default but set them to be sure */ serdev_device_set_baudrate(serdev, 9600); serdev_device_set_flow_control(serdev, false); - serdev_device_set_drvdata(serdev, dell_bl); - serdev_device_set_client_ops(serdev, &dell_uart_bl_serdev_ops); get_version[0] = DELL_SOF(GET_CMD_LEN); get_version[1] = CMD_GET_VERSION; -- 2.39.5