2022-11-29 09:36:31

by Jianglei Nie

Subject: [PATCH v3] auxdisplay: hd44780: Fix potential memory leak in hd44780_remove()

hd44780_probe() allocates a memory chunk for hd with kzalloc() and
makes "lcd->drvdata->hd44780" point to it. When we call hd44780_remove(),
we should release all relevant memory and resource. But "lcd->drvdata
->hd44780" is not released, which will lead to a memory leak.

We should release the "lcd->drvdata->hd44780" in hd44780_remove() to fix
the memory leak bug.

Fixes: 718e05ed92ec ("auxdisplay: Introduce hd44780_common.[ch]")
Reviewed-by: Andy Shevchenko <[email protected]>
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Jianglei Nie <[email protected]>
---
drivers/auxdisplay/hd44780.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/auxdisplay/hd44780.c b/drivers/auxdisplay/hd44780.c
index 8b2a0eb3f32a..d56a5d508ccd 100644
--- a/drivers/auxdisplay/hd44780.c
+++ b/drivers/auxdisplay/hd44780.c
@@ -322,8 +322,10 @@ static int hd44780_probe(struct platform_device *pdev)
static int hd44780_remove(struct platform_device *pdev)
{
struct charlcd *lcd = platform_get_drvdata(pdev);
+ struct hd44780_common *hdc = lcd->drvdata;

charlcd_unregister(lcd);
+ kfree(hdc->hd44780);
kfree(lcd->drvdata);

kfree(lcd);
--
2.25.1

2022-12-12 10:11:04

by Andy Shevchenko

Subject: Re: [PATCH v3] auxdisplay: hd44780: Fix potential memory leak in hd44780_remove()

On Tue, Nov 29, 2022 at 04:15:42PM +0800, Jianglei Nie wrote:
> hd44780_probe() allocates a memory chunk for hd with kzalloc() and
> makes "lcd->drvdata->hd44780" point to it. When we call hd44780_remove(),
> we should release all relevant memory and resource. But "lcd->drvdata
> ->hd44780" is not released, which will lead to a memory leak.
>
> We should release the "lcd->drvdata->hd44780" in hd44780_remove() to fix
> the memory leak bug.

Miguel, can this be somehow moved forward?

--
With Best Regards,
Andy Shevchenko

2022-12-13 17:58:03

by Miguel Ojeda

Subject: Re: [PATCH v3] auxdisplay: hd44780: Fix potential memory leak in hd44780_remove()

On Mon, Dec 12, 2022 at 11:00 AM Andy Shevchenko
<[email protected]> wrote:
>
> Miguel, can this be somehow moved forward?

Thanks for the ping -- queued!

Cheers,
Miguel