RE: [PATCH] driver: regmap: set debugfs_name to NULL after it is freed

[Li, Meng]

Please discard this email. There is a wrong email address in TO list.
I have sent another one.

Thanks,
Limeng

> -----Original Message-----
> From: Li, Meng <Meng.Li@xxxxxxxxxxxxx>
> Sent: Friday, February 26, 2021 10:16 AM
> To: linux-kernel@xxxxxxxxxxxxxxx; broonie@xxxxxxxxxx;
> regkh@xxxxxxxxxxxxxxxxxxx; rafael@xxxxxxxxxx
> Cc: Li, Meng <Meng.Li@xxxxxxxxxxxxx>
> Subject: [PATCH] driver: regmap: set debugfs_name to NULL after it is freed
> 
> From: Meng Li <Meng.Li@xxxxxxxxxxxxx>
> 
> There is a upstream commit cffa4b2122f5("regmap:debugfs:
> Fix a memory leak when calling regmap_attach_dev") that adds a if condition
> when create name for debugfs_name.
> With below function invoking logical, debugfs_name is freed in
> regmap_debugfs_exit(), but it is not created again because of the if
> condition introduced by above commit.
> regmap_reinit_cache()
> 	regmap_debugfs_exit()
> 	...
> 	regmap_debugfs_init()
> So, set debugfs_name to NULL after it is freed.
> 
> Fixes: cffa4b2122f5("regmap: debugfs: Fix a memory leak when calling
> regmap_attach_dev")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Meng Li <Meng.Li@xxxxxxxxxxxxx>
> ---
>  drivers/base/regmap/regmap-debugfs.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/base/regmap/regmap-debugfs.c
> b/drivers/base/regmap/regmap-debugfs.c
> index 398991381e9a..4f2ff1b2b450 100644
> --- a/drivers/base/regmap/regmap-debugfs.c
> +++ b/drivers/base/regmap/regmap-debugfs.c
> @@ -661,6 +661,7 @@ void regmap_debugfs_exit(struct regmap *map)
>  		regmap_debugfs_free_dump_cache(map);
>  		mutex_unlock(&map->cache_lock);
>  		kfree(map->debugfs_name);
> +		map->debugfs_name = NULL;
>  	} else {
>  		struct regmap_debugfs_node *node, *tmp;
> 
> --
> 2.17.1