linux-kernel - [PATCH v1 3/3] auxdisplay: lcd2s: Use proper API to free the instance of charlcd object

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Date:   Wed, 23 Feb 2022 17:47:18 +0200
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     linux-kernel@...r.kernel.org
Cc:     Miguel Ojeda <ojeda@...nel.org>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Lars Poeschel <poeschel@...onage.de>
Subject: [PATCH v1 3/3] auxdisplay: lcd2s: Use proper API to free the instance of charlcd object

While it might work, the current approach is fragile in a few ways:
- whenever members in the structure are shuffled, the pointer will be wrong
- the resource freeing may include more than covered by kfree()

Fix this by using charlcd_free() call instead of kfree().

Fixes: 8c9108d014c5 ("auxdisplay: add a driver for lcd2s character display")
Cc: Lars Poeschel <poeschel@...onage.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
---
 drivers/auxdisplay/lcd2s.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/auxdisplay/lcd2s.c b/drivers/auxdisplay/lcd2s.c
index 7b9cfbbaf007..2578b2d45439 100644
--- a/drivers/auxdisplay/lcd2s.c
+++ b/drivers/auxdisplay/lcd2s.c
@@ -336,7 +336,7 @@ static int lcd2s_i2c_probe(struct i2c_client *i2c,
 	return 0;
 
 fail1:
-	kfree(lcd);
+	charlcd_free(lcd2s->charlcd);
 	return err;
 }
 
@@ -345,7 +345,7 @@ static int lcd2s_i2c_remove(struct i2c_client *i2c)
 	struct lcd2s_data *lcd2s = i2c_get_clientdata(i2c);
 
 	charlcd_unregister(lcd2s->charlcd);
-	kfree(lcd2s->charlcd);
+	charlcd_free(lcd2s->charlcd);
 	return 0;
 }
 
-- 
2.34.1