Re: [PATCH] binder: fix memory leak in binder_init()

[Qi Zheng]

On 2023/6/26 00:16, Carlos Llamas wrote:
> On Sun, Jun 25, 2023 at 03:49:37PM +0000, Qi Zheng wrote:
> > From: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
> >
> > In binder_init(), the destruction of binder_alloc_shrinker_init() is not
> > performed in the wrong path, which will cause memory leaks. So this commit
> > introduces binder_alloc_shrinker_exit() and calls it in the wrong path to
> > fix that.
> >
> > Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
> > ---
> >   drivers/android/binder.c       | 1 +
> >   drivers/android/binder_alloc.c | 6 ++++++
> >   drivers/android/binder_alloc.h | 1 +
> >   3 files changed, 8 insertions(+)
> >
> > diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> > index 486c8271cab7..d720f93d8b19 100644
> > --- a/drivers/android/binder.c
> > +++ b/drivers/android/binder.c
> > @@ -6617,6 +6617,7 @@ static int __init binder_init(void)
> >   
> >   err_alloc_device_names_failed:
> >   	debugfs_remove_recursive(binder_debugfs_dir_entry_root);
> > +	binder_alloc_shrinker_exit();
> >   
> >   	return ret;
> >   }
> > diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
> > index 662a2a2e2e84..e3db8297095a 100644
> > --- a/drivers/android/binder_alloc.c
> > +++ b/drivers/android/binder_alloc.c
> > @@ -1087,6 +1087,12 @@ int binder_alloc_shrinker_init(void)
> >   	return ret;
> >   }
> >   
> > +void binder_alloc_shrinker_exit(void)
> > +{
> > +	unregister_shrinker(&binder_shrinker);
> > +	list_lru_destroy(&binder_alloc_lru);
> > +}
> > +
> >   /**
> >    * check_buffer() - verify that buffer/offset is safe to access
> >    * @alloc: binder_alloc for this proc
> > diff --git a/drivers/android/binder_alloc.h b/drivers/android/binder_alloc.h
> > index 138d1d5af9ce..dc1e2b01dd64 100644
> > --- a/drivers/android/binder_alloc.h
> > +++ b/drivers/android/binder_alloc.h
> > @@ -129,6 +129,7 @@ extern struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
> >   						  int pid);
> >   extern void binder_alloc_init(struct binder_alloc *alloc);
> >   extern int binder_alloc_shrinker_init(void);
> > +extern void binder_alloc_shrinker_exit(void);
> >   extern void binder_alloc_vma_close(struct binder_alloc *alloc);
> >   extern struct binder_buffer *
> >   binder_alloc_prepare_to_free(struct binder_alloc *alloc,
> > --
> > 2.30.2
>
> Thanks for the fix Qi Zheng.
>
> Acked-by: Carlos Llamas <cmllamas@xxxxxxxxxx>

Hi Greg,

Can this patch be merged? The Fixes tag is:

Fixes: f2517eb76f1f ("android: binder: Add global lru shrinker to binder")

Thanks,
Qi