[PATCH 5.15 187/262] auxdisplay: lcd2s: Use proper API to free the instance of charlcd object

From: Greg Kroah-Hartman
Date: Mon Mar 07 2022 - 05:11:51 EST


From: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

commit 9ed331f8a0fb674f4f06edf05a1687bf755af27b upstream.

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@xxxxxxxxxxx>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Signed-off-by: Miguel Ojeda <ojeda@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/auxdisplay/lcd2s.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/auxdisplay/lcd2s.c
+++ b/drivers/auxdisplay/lcd2s.c
@@ -336,7 +336,7 @@ static int lcd2s_i2c_probe(struct i2c_cl
return 0;

fail1:
- kfree(lcd);
+ charlcd_free(lcd2s->charlcd);
return err;
}

@@ -345,7 +345,7 @@ static int lcd2s_i2c_remove(struct i2c_c
struct lcd2s_data *lcd2s = i2c_get_clientdata(i2c);

charlcd_unregister(lcd2s->charlcd);
- kfree(lcd2s->charlcd);
+ charlcd_free(lcd2s->charlcd);
return 0;
}