From:   Zheng Wang <zyytlz.wz@163.com>
To:     dri-devel@lists.freedesktop.org
Cc:     andrzej.hajda@intel.com, neil.armstrong@linaro.org,
        jonas@kwiboo.se, airlied@gmail.com, daniel@ffwll.ch,
        linux-kernel@vger.kernel.org, hackerzheng666@gmail.com,
        1395428693sheep@gmail.com, alex000young@gmail.com,
        Zheng Wang <zyytlz.wz@163.com>
Subject: [PATCH v2] drm/bridge: adv7511: fix race condition bug in adv7511_remove due to unfinished work
Date:   Fri, 17 Mar 2023 00:04:02 +0800
Message-Id: <20230316160402.1566483-1-zyytlz.wz@163.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

In adv7511_probe, adv7511->hpd_work is bound with adv7511_hpd_work.
If we call adv7511_remove with a unfinished work. There may be a 
race condition where bridge->hpd_mutex was destroyed by 
drm_bridge_remove and used in adv7511_hpd_work in drm_bridge_hpd_notify.

Fix it by canceling the work before cleanup in adv7511_remove.
Fixes: 518cb7057a59 ("drm/bridge: adv7511: Use work_struct to defer hotplug handing to out of irq context")
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
---
 drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
index ddceafa7b637..9bf72dd6c1d3 100644
--- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
+++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
@@ -1349,6 +1349,7 @@ static void adv7511_remove(struct i2c_client *i2c)
 {
 	struct adv7511 *adv7511 = i2c_get_clientdata(i2c);
 
+	cancel_work_sync(&adv7511->hpd_work);
 	adv7511_uninit_regulators(adv7511);
 
 	drm_bridge_remove(&adv7511->bridge);
-- 
2.25.1