drm/vmwgfx: Make sure backup_handle is always valid

When vmw_gb_surface_define_ioctl() is called with an existing buffer,
we end up returning an uninitialized variable in the backup_handle.

The fix is to first initialize backup_handle to 0 just to be sure, and
second, when a user-provided buffer is found, we will use the
req->buffer_handle as the backup_handle.

Cc: <stable@vger.kernel.org>
Reported-by: Murray McAllister <murray.mcallister@insomniasec.com>
Signed-off-by: Sinclair Yeh <syeh@vmware.com>
Reviewed-by: Deepak Rawat <drawat@vmware.com>
This commit is contained in:
Sinclair Yeh 2017-06-02 07:50:57 +02:00 committed by Thomas Hellstrom
parent f0c62e9878
commit 07678eca2c

View file

@ -1274,7 +1274,7 @@ int vmw_gb_surface_define_ioctl(struct drm_device *dev, void *data,
struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile;
int ret;
uint32_t size;
uint32_t backup_handle;
uint32_t backup_handle = 0;
if (req->multisample_count != 0)
return -EINVAL;
@ -1317,12 +1317,16 @@ int vmw_gb_surface_define_ioctl(struct drm_device *dev, void *data,
ret = vmw_user_dmabuf_lookup(tfile, req->buffer_handle,
&res->backup,
&user_srf->backup_base);
if (ret == 0 && res->backup->base.num_pages * PAGE_SIZE <
res->backup_size) {
DRM_ERROR("Surface backup buffer is too small.\n");
vmw_dmabuf_unreference(&res->backup);
ret = -EINVAL;
goto out_unlock;
if (ret == 0) {
if (res->backup->base.num_pages * PAGE_SIZE <
res->backup_size) {
DRM_ERROR("Surface backup buffer is too small.\n");
vmw_dmabuf_unreference(&res->backup);
ret = -EINVAL;
goto out_unlock;
} else {
backup_handle = req->buffer_handle;
}
}
} else if (req->drm_surface_flags & drm_vmw_surface_flag_create_buffer)
ret = vmw_user_dmabuf_alloc(dev_priv, tfile,