tee: fix memory leak in tee_dyn_shm_alloc_helper

[PATCH] tee: fix memory leak in tee_dyn_shm_alloc_helper

Posted by Pei Xiao 6 months, 2 weeks ago

When shm_register() fails in tee_dyn_shm_alloc_helper(), the pre-allocated
pages array is not freed, resulting in a memory leak.

Fixes: cf4441503e20 ("tee: optee: Move pool_op helper functions")
Signed-off-by: Pei Xiao <xiaopei01@kylinos.cn>
---
 drivers/tee/tee_shm.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index 915239b033f5..2a7d253d9c55 100644
--- a/drivers/tee/tee_shm.c
+++ b/drivers/tee/tee_shm.c
@@ -230,7 +230,7 @@ int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align,
 	pages = kcalloc(nr_pages, sizeof(*pages), GFP_KERNEL);
 	if (!pages) {
 		rc = -ENOMEM;
-		goto err;
+		goto err_pages;
 	}
 
 	for (i = 0; i < nr_pages; i++)
@@ -243,11 +243,13 @@ int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align,
 		rc = shm_register(shm->ctx, shm, pages, nr_pages,
 				  (unsigned long)shm->kaddr);
 		if (rc)
-			goto err;
+			goto err_kfree;
 	}
 
 	return 0;
-err:
+err_kfree:
+	kfree(pages);
+err_pages:
 	free_pages_exact(shm->kaddr, shm->size);
 	shm->kaddr = NULL;
 	return rc;
-- 
2.25.1

Re: [PATCH] tee: fix memory leak in tee_dyn_shm_alloc_helper

Posted by Markus Elfring 6 months, 2 weeks ago

> When shm_register() fails in tee_dyn_shm_alloc_helper(), the pre-allocated
> pages array is not freed, resulting in a memory leak.

See also:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.16#n94

Regards,
Markus

Re: [PATCH] tee: fix memory leak in tee_dyn_shm_alloc_helper

Posted by Sumit Garg 6 months, 2 weeks ago

On Wed, Jul 23, 2025 at 02:22:41PM +0800, Pei Xiao wrote:
> When shm_register() fails in tee_dyn_shm_alloc_helper(), the pre-allocated
> pages array is not freed, resulting in a memory leak.
> 
> Fixes: cf4441503e20 ("tee: optee: Move pool_op helper functions")
> Signed-off-by: Pei Xiao <xiaopei01@kylinos.cn>
> ---
>  drivers/tee/tee_shm.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)

Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>

-Sumit

> 
> diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
> index 915239b033f5..2a7d253d9c55 100644
> --- a/drivers/tee/tee_shm.c
> +++ b/drivers/tee/tee_shm.c
> @@ -230,7 +230,7 @@ int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align,
>  	pages = kcalloc(nr_pages, sizeof(*pages), GFP_KERNEL);
>  	if (!pages) {
>  		rc = -ENOMEM;
> -		goto err;
> +		goto err_pages;
>  	}
>  
>  	for (i = 0; i < nr_pages; i++)
> @@ -243,11 +243,13 @@ int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align,
>  		rc = shm_register(shm->ctx, shm, pages, nr_pages,
>  				  (unsigned long)shm->kaddr);
>  		if (rc)
> -			goto err;
> +			goto err_kfree;
>  	}
>  
>  	return 0;
> -err:
> +err_kfree:
> +	kfree(pages);
> +err_pages:
>  	free_pages_exact(shm->kaddr, shm->size);
>  	shm->kaddr = NULL;
>  	return rc;
> -- 
> 2.25.1
>

Re: [PATCH] tee: fix memory leak in tee_dyn_shm_alloc_helper

Posted by Jens Wiklander 6 months, 1 week ago

On Tue, Jul 29, 2025 at 11:27 AM Sumit Garg <sumit.garg@kernel.org> wrote:
>
> On Wed, Jul 23, 2025 at 02:22:41PM +0800, Pei Xiao wrote:
> > When shm_register() fails in tee_dyn_shm_alloc_helper(), the pre-allocated
> > pages array is not freed, resulting in a memory leak.
> >
> > Fixes: cf4441503e20 ("tee: optee: Move pool_op helper functions")
> > Signed-off-by: Pei Xiao <xiaopei01@kylinos.cn>
> > ---
> >  drivers/tee/tee_shm.c | 8 +++++---
> >  1 file changed, 5 insertions(+), 3 deletions(-)
>
> Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>

Looks good. I'm picking up this.

Thanks,
Jens

>
> -Sumit
>
> >
> > diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
> > index 915239b033f5..2a7d253d9c55 100644
> > --- a/drivers/tee/tee_shm.c
> > +++ b/drivers/tee/tee_shm.c
> > @@ -230,7 +230,7 @@ int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align,
> >       pages = kcalloc(nr_pages, sizeof(*pages), GFP_KERNEL);
> >       if (!pages) {
> >               rc = -ENOMEM;
> > -             goto err;
> > +             goto err_pages;
> >       }
> >
> >       for (i = 0; i < nr_pages; i++)
> > @@ -243,11 +243,13 @@ int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align,
> >               rc = shm_register(shm->ctx, shm, pages, nr_pages,
> >                                 (unsigned long)shm->kaddr);
> >               if (rc)
> > -                     goto err;
> > +                     goto err_kfree;
> >       }
> >
> >       return 0;
> > -err:
> > +err_kfree:
> > +     kfree(pages);
> > +err_pages:
> >       free_pages_exact(shm->kaddr, shm->size);
> >       shm->kaddr = NULL;
> >       return rc;
> > --
> > 2.25.1
> >