[PATCH] vfio/common: Do not g_free in vfio_get_iommu_info

[Nicolin Chen]

Its caller vfio_connect_container() assigns a default value
to info->iova_pgsizes, even if vfio_get_iommu_info() fails.
This would result in a "Segmentation fault" error, when the
VFIO_IOMMU_GET_INFO ioctl errors out.

Since the caller has g_free already, drop the g_free in its
rollback routine and add a line of comments to highlight it.

Fixes: 87ea529c50 ("vfio: Get migration capability flags for container")
Cc: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
 hw/vfio/common.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index ace9562a9b..51b2e05c76 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -1940,6 +1940,7 @@ static int vfio_init_container(VFIOContainer *container, 
int group_fd,
     return 0;
 }
 
+/* The caller is responsible for g_free(*info) */
 static int vfio_get_iommu_info(VFIOContainer *container,
                                struct vfio_iommu_type1_info **info)
 {
@@ -1951,8 +1952,6 @@ again:
     (*info)->argsz = argsz;
 
     if (ioctl(container->fd, VFIO_IOMMU_GET_INFO, *info)) {
-        g_free(*info);
-        *info = NULL;
         return -errno;
     }
 
-- 
2.17.1