Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.31 as permitted sender) client-ip=23.128.96.31;
From:   Maxime Ripard <mripard@kernel.org>
Date:   Tue, 28 Nov 2023 11:24:16 +0100
Subject: [PATCH v4 05/45] drm/connector: Check drm_connector_init pointers
 arguments
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
Message-Id: <20231128-kms-hdmi-connector-state-v4-5-c7602158306e@kernel.org>
References: <20231128-kms-hdmi-connector-state-v4-0-c7602158306e@kernel.org>
In-Reply-To: <20231128-kms-hdmi-connector-state-v4-0-c7602158306e@kernel.org>
To:     Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>, Emma Anholt <emma@anholt.net>,
        Jonathan Corbet <corbet@lwn.net>,
        Sandy Huang <hjc@rock-chips.com>,
        =?utf-8?q?Heiko_St=C3=BCbner?= <heiko@sntech.de>,
        Chen-Yu Tsai <wens@csie.org>,
        Jernej Skrabec <jernej.skrabec@gmail.com>,
        Samuel Holland <samuel@sholland.org>
Cc:     Hans Verkuil <hverkuil@xs4all.nl>, dri-devel@lists.freedesktop.org,
        linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-media@vger.kernel.org,
        linux-rockchip@lists.infradead.org, linux-sunxi@lists.linux.dev,
        Maxime Ripard <mripard@kernel.org>
Precedence: bulk

All the drm_connector_init variants take at least a pointer to the
device, connector and hooks implementation.

However, none of them check their value before dereferencing those
pointers which can lead to a NULL-pointer dereference if the author
isn't careful.

Let's test those pointers instead and error out if any is NULL.

Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/drm_connector.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index b0516505f7ae..2f60755dccdd 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -229,6 +229,9 @@ static int __drm_connector_init(struct drm_device *dev,
 	struct ida *connector_ida =
 		&drm_connector_enum_list[connector_type].ida;
 
+	if (!dev || !connector || !funcs)
+		return -EINVAL;
+
 	WARN_ON(drm_drv_uses_atomic_modeset(dev) &&
 		(!funcs->atomic_destroy_state ||
 		 !funcs->atomic_duplicate_state));

-- 
2.41.0