[PATCH v2] vfio: Fix memory leak of hostwin

[PATCH v2] vfio: Fix memory leak of hostwin

[Peng Liang]

hostwin is allocated and added to hostwin_list in vfio_host_win_add, but
it is only deleted from hostwin_list in vfio_host_win_del, which causes
a memory leak.  Also, freeing all elements in hostwin_list is missing in
vfio_disconnect_container.

Fix: 2e4109de8e58 ("vfio/spapr: Create DMA window dynamically (SPAPR IOMMU v2)")
CC: qemu-stable@nongnu.org
Signed-off-by: Peng Liang <liangpeng10@huawei.com>
---
v1 -> v2:
- Don't change to _SAFE variant in vfio_host_win_del. [Alex]
---
 hw/vfio/common.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index dd387b0d3959..080046e3f511 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -551,6 +551,7 @@ static int vfio_host_win_del(VFIOContainer *container, hwaddr min_iova,
     QLIST_FOREACH(hostwin, &container->hostwin_list, hostwin_next) {
         if (hostwin->min_iova == min_iova && hostwin->max_iova == max_iova) {
             QLIST_REMOVE(hostwin, hostwin_next);
+            g_free(hostwin);
             return 0;
         }
     }
@@ -2239,6 +2240,7 @@ static void vfio_disconnect_container(VFIOGroup *group)
     if (QLIST_EMPTY(&container->group_list)) {
         VFIOAddressSpace *space = container->space;
         VFIOGuestIOMMU *giommu, *tmp;
+        VFIOHostDMAWindow *hostwin, *next;
 
         QLIST_REMOVE(container, next);
 
@@ -2249,6 +2251,12 @@ static void vfio_disconnect_container(VFIOGroup *group)
             g_free(giommu);
         }
 
+        QLIST_FOREACH_SAFE(hostwin, &container->hostwin_list, hostwin_next,
+                           next) {
+            QLIST_REMOVE(hostwin, hostwin_next);
+            g_free(hostwin);
+        }
+
         trace_vfio_disconnect_container(container->fd);
         close(container->fd);
         g_free(container);
-- 
2.33.1

Re: [PATCH v2] vfio: Fix memory leak of hostwin

[Alex Williamson]

On Wed, 17 Nov 2021 09:47:39 +0800
Peng Liang <liangpeng10@huawei.com> wrote:

> hostwin is allocated and added to hostwin_list in vfio_host_win_add, but
> it is only deleted from hostwin_list in vfio_host_win_del, which causes
> a memory leak.  Also, freeing all elements in hostwin_list is missing in
> vfio_disconnect_container.
> 
> Fix: 2e4109de8e58 ("vfio/spapr: Create DMA window dynamically (SPAPR IOMMU v2)")
> CC: qemu-stable@nongnu.org
> Signed-off-by: Peng Liang <liangpeng10@huawei.com>
> ---
> v1 -> v2:
> - Don't change to _SAFE variant in vfio_host_win_del. [Alex]
> ---
>  hw/vfio/common.c | 8 ++++++++
>  1 file changed, 8 insertions(+)

Thanks, pull request sent to include this in 6.2.

Alex

> 
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index dd387b0d3959..080046e3f511 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -551,6 +551,7 @@ static int vfio_host_win_del(VFIOContainer *container, hwaddr min_iova,
>      QLIST_FOREACH(hostwin, &container->hostwin_list, hostwin_next) {
>          if (hostwin->min_iova == min_iova && hostwin->max_iova == max_iova) {
>              QLIST_REMOVE(hostwin, hostwin_next);
> +            g_free(hostwin);
>              return 0;
>          }
>      }
> @@ -2239,6 +2240,7 @@ static void vfio_disconnect_container(VFIOGroup *group)
>      if (QLIST_EMPTY(&container->group_list)) {
>          VFIOAddressSpace *space = container->space;
>          VFIOGuestIOMMU *giommu, *tmp;
> +        VFIOHostDMAWindow *hostwin, *next;
>  
>          QLIST_REMOVE(container, next);
>  
> @@ -2249,6 +2251,12 @@ static void vfio_disconnect_container(VFIOGroup *group)
>              g_free(giommu);
>          }
>  
> +        QLIST_FOREACH_SAFE(hostwin, &container->hostwin_list, hostwin_next,
> +                           next) {
> +            QLIST_REMOVE(hostwin, hostwin_next);
> +            g_free(hostwin);
> +        }
> +
>          trace_vfio_disconnect_container(container->fd);
>          close(container->fd);
>          g_free(container);