Re: [PATCH 5.10 086/103] regmap: debugfs: Fix a memory leak when calling regmap_attach_dev

On Fri, Jan 15, 2021 at 09:18:19PM +0100, Pavel Machek wrote:

Hi!

...

From: Xiaolei Wang xiaolei.wang@windriver.com

commit cffa4b2122f5f3e53cf3d529bbc74651f95856d5 upstream.

After initializing the regmap through syscon_regmap_lookup_by_compatible, then regmap_attach_dev to the device, because the debugfs_name has been allocated, there is no need to redistribute it again

? redistribute?

Anyway, this patch is clearly buggy:

...

if (!strcmp(name, "dummy")) {

• kfree(map->debugfs_name);
  

• if (!map->debugfs_name)
  

• 	kfree(map->debugfs_name);
  

It runs kfree only if the variable is NULL. That's clearly useless, kfree(NULL) is NOP, and this causes memory leak.

Fixed by commit f6bcb4c7f366 ("regmap: debugfs: Fix a reversed if statement in regmap_debugfs_init()") in mainline.

Cheers, Nathan