2019-08-08 05:16:52

by Wenwen Wang

Subject: [PATCH] sound: fix a memory leak bug

In sound_insert_unit(), the controlling structure 's' is allocated through
kmalloc(). Then it is added to the sound driver list by invoking
__sound_insert_unit(). Later on, if __register_chrdev() fails, 's' is
removed from the list through __sound_remove_unit(). If 'index' is not less
than 0, -EBUSY is returned to indicate the error. However, 's' is not
deallocated on this execution path, leading to a memory leak bug.

To fix the above issue, free 's' before -EBUSY is returned.

Signed-off-by: Wenwen Wang <[email protected]>
---
sound/sound_core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sound/sound_core.c b/sound/sound_core.c
index b730d97..90d118c 100644
--- a/sound/sound_core.c
+++ b/sound/sound_core.c
@@ -275,7 +275,8 @@ static int sound_insert_unit(struct sound_unit **list, const struct file_operati
goto retry;
}
spin_unlock(&sound_loader_lock);
- return -EBUSY;
+ r = -EBUSY;
+ goto fail;
}
}

--
2.7.4

2019-08-08 06:23:06

by Takashi Iwai

Subject: Re: [PATCH] sound: fix a memory leak bug

On Thu, 08 Aug 2019 07:15:21 +0200,
Wenwen Wang wrote:
>
> In sound_insert_unit(), the controlling structure 's' is allocated through
> kmalloc(). Then it is added to the sound driver list by invoking
> __sound_insert_unit(). Later on, if __register_chrdev() fails, 's' is
> removed from the list through __sound_remove_unit(). If 'index' is not less
> than 0, -EBUSY is returned to indicate the error. However, 's' is not
> deallocated on this execution path, leading to a memory leak bug.
>
> To fix the above issue, free 's' before -EBUSY is returned.
>
> Signed-off-by: Wenwen Wang <[email protected]>

Oh, it's a really old bug. Applied now.

Thanks!


Takashi