[PATCH] xen/arm: optee: fix possible memory leaks

Volodymyr Babchuk posted 1 patch 2 weeks ago
xen/arch/arm/tee/optee.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

[PATCH] xen/arm: optee: fix possible memory leaks

Posted by Volodymyr Babchuk 2 weeks ago
translate_noncontig() allocates domheap page for translated list
before calling to allocate_optee_shm_buf(), which can fail for number
of reason. Anyways, after fail we need to free the allocated page(s).

Another leak is possible if the same translate_noncontig() function
fails to get domain page. In this case it should free allocated
optee_shm_buf prior exit. This will also free allocated domheap page.

Signed-off-by: Volodymyr Babchuk <volodymyr_babchuk@epam.com>
---
 xen/arch/arm/tee/optee.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/tee/optee.c b/xen/arch/arm/tee/optee.c
index 6df0d44eb9..131d2f9a8a 100644
--- a/xen/arch/arm/tee/optee.c
+++ b/xen/arch/arm/tee/optee.c
@@ -781,7 +781,10 @@ static int translate_noncontig(struct optee_domain *ctx,
     optee_shm_buf = allocate_optee_shm_buf(ctx, param->u.tmem.shm_ref,
                                            pg_count, xen_pgs, order);
     if ( IS_ERR(optee_shm_buf) )
+    {
+        free_domheap_pages(xen_pgs, order);
         return PTR_ERR(optee_shm_buf);
+    }
 
     gfn = gaddr_to_gfn(param->u.tmem.buf_ptr &
                        ~(OPTEE_MSG_NONCONTIG_PAGE_SIZE - 1));
@@ -807,7 +810,7 @@ static int translate_noncontig(struct optee_domain *ctx,
         {
             guest_pg = get_domain_ram_page(gfn);
             if ( !guest_pg )
-                return -EINVAL;
+                goto free_shm_buf;
 
             guest_data = __map_domain_page(guest_pg);
             xen_data = __map_domain_page(xen_pgs);
@@ -854,6 +857,7 @@ err_unmap:
     unmap_domain_page(guest_data);
     unmap_domain_page(xen_data);
     put_page(guest_pg);
+free_shm_buf:
     free_optee_shm_buf(ctx, optee_shm_buf->cookie);
 
     return -EINVAL;
-- 
2.33.0

Re: [PATCH] xen/arm: optee: fix possible memory leaks

Posted by Stefano Stabellini 2 weeks ago
On Thu, 7 Oct 2021, Volodymyr Babchuk wrote:
> translate_noncontig() allocates domheap page for translated list
> before calling to allocate_optee_shm_buf(), which can fail for number
> of reason. Anyways, after fail we need to free the allocated page(s).
> 
> Another leak is possible if the same translate_noncontig() function
> fails to get domain page. In this case it should free allocated
> optee_shm_buf prior exit. This will also free allocated domheap page.
> 
> Signed-off-by: Volodymyr Babchuk <volodymyr_babchuk@epam.com>

Acked-by: Stefano Stabellini <sstabellini@kernel.org>


> ---
>  xen/arch/arm/tee/optee.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/xen/arch/arm/tee/optee.c b/xen/arch/arm/tee/optee.c
> index 6df0d44eb9..131d2f9a8a 100644
> --- a/xen/arch/arm/tee/optee.c
> +++ b/xen/arch/arm/tee/optee.c
> @@ -781,7 +781,10 @@ static int translate_noncontig(struct optee_domain *ctx,
>      optee_shm_buf = allocate_optee_shm_buf(ctx, param->u.tmem.shm_ref,
>                                             pg_count, xen_pgs, order);
>      if ( IS_ERR(optee_shm_buf) )
> +    {
> +        free_domheap_pages(xen_pgs, order);
>          return PTR_ERR(optee_shm_buf);
> +    }
>  
>      gfn = gaddr_to_gfn(param->u.tmem.buf_ptr &
>                         ~(OPTEE_MSG_NONCONTIG_PAGE_SIZE - 1));
> @@ -807,7 +810,7 @@ static int translate_noncontig(struct optee_domain *ctx,
>          {
>              guest_pg = get_domain_ram_page(gfn);
>              if ( !guest_pg )
> -                return -EINVAL;
> +                goto free_shm_buf;
>  
>              guest_data = __map_domain_page(guest_pg);
>              xen_data = __map_domain_page(xen_pgs);
> @@ -854,6 +857,7 @@ err_unmap:
>      unmap_domain_page(guest_data);
>      unmap_domain_page(xen_data);
>      put_page(guest_pg);
> +free_shm_buf:
>      free_optee_shm_buf(ctx, optee_shm_buf->cookie);
>  
>      return -EINVAL;
> -- 
> 2.33.0
>