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 C298F46EF73; Tue, 21 Jul 2026 20:28:54 +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=1784665735; cv=none; b=XYIM7w6CWkilsnjpi519W22iM0a33O9yNfBKoYB540QjnQQ0rsmLmr64Ca94T9E+oamaTqzDOWj3O9lyXIh9LegKSQZNTjkNDx5sswii24d/uN1sWYmteedcG/PaJsgaViJuc3+1a55kUSonHgf6EpXTHGchb1x/W5QyZk2Sdu0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784665735; c=relaxed/simple; bh=vQEDhEocsYCjP2TQoV6pGJbkVoLI5uzDSGgZrfS5P18=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cL+ZCl/9Wp/Cc6ImWdzSuWQHY5FpYf22RkdH8y5s92hz28CapxvB8ChQBTBCKZ/sRJi4MYse1cQwZ2CxV3Me1d8hhY/EM6ERpPcLw4PYraIoVmUgJASWpK0yV2C8fnr8Iu1shgz8ozwvL1TuLg4cN6chmXphbdSfQZEodnv1APM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=2Lm2MDbJ; 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="2Lm2MDbJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 34DF01F00A3A; Tue, 21 Jul 2026 20:28:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784665734; bh=UaZ1RXM5IBjITGifMrNGnlQUYx21ymHTniIlqeFeb9I=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=2Lm2MDbJX5dPDNqdQqV7PJhUqqzQbVaR75ftNGbQhdxS7WdUAzTlK2FX9pNsGvGgB 7nacITf35ehHARm3oZ57NiwT2No/HzYxu0eNyGKPBUY4ObrBDHQCjkGIiqnFgdMafL h3ev84rKbLGfQV+ud/ioI5lnpajen/3jAyJ3D5Ow= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Rafael J. Wysocki (Intel)" , Saravana Kannan , Danilo Krummrich , Sasha Levin Subject: [PATCH 6.6 0372/1266] driver core: use READ_ONCE() for dev->driver in dev_has_sync_state() Date: Tue, 21 Jul 2026 17:13:29 +0200 Message-ID: <20260721152450.150294883@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152441.786066624@linuxfoundation.org> References: <20260721152441.786066624@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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Danilo Krummrich [ Upstream commit e9506871a8ea304cde48ff4a57226df2aadddae3 ] dev_has_sync_state() reads dev->driver twice without holding device_lock() -- once for the NULL check and once to dereference ->sync_state. Some callers only hold device_links_write_lock, which doesn't prevent a concurrent unbind from clearing dev->driver via device_unbind_cleanup(). Fix it by reading dev->driver exactly once with READ_ONCE(), pairing with the WRITE_ONCE() in device_set_driver(). Link: https://lore.kernel.org/driver-core/DHW8QPU1VU1F.3P6PH69HLFBYC@kernel.org/ Fixes: ac338acf514e ("driver core: Add dev_has_sync_state()") Reviewed-by: Rafael J. Wysocki (Intel) Acked-by: Greg Kroah-Hartman Reviewed-by: Saravana Kannan Link: https://patch.msgid.link/20260418162221.1121873-1-dakr@kernel.org Signed-off-by: Danilo Krummrich Signed-off-by: Sasha Levin --- include/linux/device.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/include/linux/device.h b/include/linux/device.h index 2a9017eec15c24..f4b321236c66f4 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1125,9 +1125,12 @@ static inline struct device_node *dev_of_node(struct device *dev) static inline bool dev_has_sync_state(struct device *dev) { + struct device_driver *drv; + if (!dev) return false; - if (dev->driver && dev->driver->sync_state) + drv = READ_ONCE(dev->driver); + if (drv && drv->sync_state) return true; if (dev->bus && dev->bus->sync_state) return true; -- 2.53.0