From nobody Sat Oct 4 06:34:47 2025 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 8AE922D9EF8; Wed, 20 Aug 2025 08:17:33 +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=1755677853; cv=none; b=cfLW3hq307VGw2whNG8Q3c38I5A40FGDPJzPfUJx4toic2Tj/za/bQ2DYWpLQYD90DB4GKO2+d6xr5oqs26tyYyojNv6LTZ959cQXqXIAU1r+8e7SHiDBTLe0uP0jk4ZLx4WOncKMHPk7aDf8iHlIh9Y12dEwIpj0tyde1E/zX0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755677853; c=relaxed/simple; bh=7fsMezvoDQEYp2ae8oSLemUvrmjXu6gJVUF5jYa8vMs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JPmMrVc9tGrigMVt0OHmxZMtz12zHdI+2+srw9jSXvNbr39CoWUsM5iBtn6mrjWNeNG8FYnXI9dgBKvnPtukb9ZiwrglAXg0Ec2UtltaIOTYqTVjU/ebyyE9t5VIL8Lxd7sDBIAI8NiJrAGFqe3x7ItgPU13LRB8mTLaaNEVGs8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=R0e2KWhX; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="R0e2KWhX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 95987C113D0; Wed, 20 Aug 2025 08:17:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755677853; bh=7fsMezvoDQEYp2ae8oSLemUvrmjXu6gJVUF5jYa8vMs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=R0e2KWhXHtI1VnTHl1Fsv57y9Ww9+SKlB3nGZM6pSL3YwAMPT8McXEO95tHkLq2Op /iPfv6auBcQxG49322bKL+ngXCmjs0yXnh32/eUkQ0X6FKF9yJDAZR49il2UnE/1jD UAqUu0MPttMzasmpozO66zsy60OuZOgaKVcUT8Dg8PBfHWHb/bBVJ5gov+C5ktDLDB A72KVVim2068GkQAznQ3vsxA99zdNN9LyOyIMZNJwbb4KTD/sYu50fDWSQRBJAJubj RvdtSGsjfg8aTHFA4Au1TJa1WLDFkZB1c3Rqqn5JRZzXJuQYZrWhZKBvFQW8VRXAWY apgMxufqMcEWA== From: Tzung-Bi Shih To: Benson Leung , Greg Kroah-Hartman , "Rafael J . Wysocki" , Danilo Krummrich Cc: Jonathan Corbet , Shuah Khan , Dawid Niedzwiecki , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, chrome-platform@lists.linux.dev, linux-kselftest@vger.kernel.org, tzungbi@kernel.org Subject: [PATCH v2 4/5] platform/chrome: Protect cros_ec_device lifecycle with revocable Date: Wed, 20 Aug 2025 08:16:44 +0000 Message-ID: <20250820081645.847919-5-tzungbi@kernel.org> X-Mailer: git-send-email 2.51.0.rc1.167.g924127e9c0-goog In-Reply-To: <20250820081645.847919-1-tzungbi@kernel.org> References: <20250820081645.847919-1-tzungbi@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The cros_ec_device can be unregistered when the underlying device is removed. Other kernel drivers that interact with the EC may hold a pointer to the cros_ec_device, creating a risk of a use-after-free error if the EC device is removed while still being referenced. To prevent this, leverage the revocable and convert the underlying device drivers to resource providers of cros_ec_device. Signed-off-by: Tzung-Bi Shih --- v2: - Rename "ref_proxy" -> "revocable". v1: https://lore.kernel.org/chrome-platform/20250814091020.1302888-3-tzungb= i@kernel.org drivers/platform/chrome/cros_ec_i2c.c | 5 +++++ drivers/platform/chrome/cros_ec_ishtp.c | 5 +++++ drivers/platform/chrome/cros_ec_lpc.c | 5 +++++ drivers/platform/chrome/cros_ec_rpmsg.c | 5 +++++ drivers/platform/chrome/cros_ec_spi.c | 4 ++++ drivers/platform/chrome/cros_ec_uart.c | 5 +++++ include/linux/platform_data/cros_ec_proto.h | 4 ++++ 7 files changed, 33 insertions(+) diff --git a/drivers/platform/chrome/cros_ec_i2c.c b/drivers/platform/chrom= e/cros_ec_i2c.c index 38af97cdaab2..68a8d2c65ca3 100644 --- a/drivers/platform/chrome/cros_ec_i2c.c +++ b/drivers/platform/chrome/cros_ec_i2c.c @@ -12,6 +12,7 @@ #include #include #include +#include #include =20 #include "cros_ec.h" @@ -296,6 +297,10 @@ static int cros_ec_i2c_probe(struct i2c_client *client) if (!ec_dev) return -ENOMEM; =20 + ec_dev->revocable_provider =3D devm_revocable_provider_alloc(dev, ec_dev); + if (!ec_dev->revocable_provider) + return -ENOMEM; + i2c_set_clientdata(client, ec_dev); ec_dev->dev =3D dev; ec_dev->priv =3D client; diff --git a/drivers/platform/chrome/cros_ec_ishtp.c b/drivers/platform/chr= ome/cros_ec_ishtp.c index 7e7190b30cbb..3467b4e9ceb5 100644 --- a/drivers/platform/chrome/cros_ec_ishtp.c +++ b/drivers/platform/chrome/cros_ec_ishtp.c @@ -12,6 +12,7 @@ #include #include #include +#include #include =20 #include "cros_ec.h" @@ -547,6 +548,10 @@ static int cros_ec_dev_init(struct ishtp_cl_data *clie= nt_data) if (!ec_dev) return -ENOMEM; =20 + ec_dev->revocable_provider =3D devm_revocable_provider_alloc(dev, ec_dev); + if (!ec_dev->revocable_provider) + return -ENOMEM; + client_data->ec_dev =3D ec_dev; dev->driver_data =3D ec_dev; =20 diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrom= e/cros_ec_lpc.c index 7d9a78289c96..77bdaf430979 100644 --- a/drivers/platform/chrome/cros_ec_lpc.c +++ b/drivers/platform/chrome/cros_ec_lpc.c @@ -23,6 +23,7 @@ #include #include #include +#include #include =20 #include "cros_ec.h" @@ -641,6 +642,10 @@ static int cros_ec_lpc_probe(struct platform_device *p= dev) if (!ec_dev) return -ENOMEM; =20 + ec_dev->revocable_provider =3D devm_revocable_provider_alloc(dev, ec_dev); + if (!ec_dev->revocable_provider) + return -ENOMEM; + platform_set_drvdata(pdev, ec_dev); ec_dev->dev =3D dev; ec_dev->phys_name =3D dev_name(dev); diff --git a/drivers/platform/chrome/cros_ec_rpmsg.c b/drivers/platform/chr= ome/cros_ec_rpmsg.c index bc2666491db1..04d886829aa7 100644 --- a/drivers/platform/chrome/cros_ec_rpmsg.c +++ b/drivers/platform/chrome/cros_ec_rpmsg.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include =20 @@ -220,6 +221,10 @@ static int cros_ec_rpmsg_probe(struct rpmsg_device *rp= dev) if (!ec_dev) return -ENOMEM; =20 + ec_dev->revocable_provider =3D devm_revocable_provider_alloc(dev, ec_dev); + if (!ec_dev->revocable_provider) + return -ENOMEM; + ec_rpmsg =3D devm_kzalloc(dev, sizeof(*ec_rpmsg), GFP_KERNEL); if (!ec_rpmsg) return -ENOMEM; diff --git a/drivers/platform/chrome/cros_ec_spi.c b/drivers/platform/chrom= e/cros_ec_spi.c index 8ca0f854e7ac..1b611ec5c9c1 100644 --- a/drivers/platform/chrome/cros_ec_spi.c +++ b/drivers/platform/chrome/cros_ec_spi.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include #include @@ -752,6 +753,9 @@ static int cros_ec_spi_probe(struct spi_device *spi) ec_dev =3D devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL); if (!ec_dev) return -ENOMEM; + ec_dev->revocable_provider =3D devm_revocable_provider_alloc(dev, ec_dev); + if (!ec_dev->revocable_provider) + return -ENOMEM; =20 /* Check for any DT properties */ cros_ec_spi_dt_probe(ec_spi, dev); diff --git a/drivers/platform/chrome/cros_ec_uart.c b/drivers/platform/chro= me/cros_ec_uart.c index 19c179d49c90..b234f13a92a9 100644 --- a/drivers/platform/chrome/cros_ec_uart.c +++ b/drivers/platform/chrome/cros_ec_uart.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -263,6 +264,10 @@ static int cros_ec_uart_probe(struct serdev_device *se= rdev) if (!ec_dev) return -ENOMEM; =20 + ec_dev->revocable_provider =3D devm_revocable_provider_alloc(dev, ec_dev); + if (!ec_dev->revocable_provider) + return -ENOMEM; + serdev_device_set_drvdata(serdev, ec_dev); init_waitqueue_head(&ec_uart->response.wait_queue); =20 diff --git a/include/linux/platform_data/cros_ec_proto.h b/include/linux/pl= atform_data/cros_ec_proto.h index 3ec24f445c29..0c3df0bb0aa4 100644 --- a/include/linux/platform_data/cros_ec_proto.h +++ b/include/linux/platform_data/cros_ec_proto.h @@ -12,6 +12,7 @@ #include #include #include +#include =20 #include =20 @@ -158,6 +159,7 @@ struct cros_ec_command { * @pd: The platform_device used by the mfd driver to interface with the * PD behind an EC. * @panic_notifier: EC panic notifier. + * @revocable_provider: The revocable_provider to this device. */ struct cros_ec_device { /* These are used by other drivers that want to talk to the EC */ @@ -203,6 +205,8 @@ struct cros_ec_device { struct platform_device *pd; =20 struct blocking_notifier_head panic_notifier; + + struct revocable_provider *revocable_provider; }; =20 /** --=20 2.51.0.rc1.167.g924127e9c0-goog