[PATCH v2] virt: vbox: fix memory leak in hgcm_call_preprocess_linaddr

[Navid Emamdoost]

In hgcm_call_preprocess_linaddr memory is allocated for bounce_buf but
is not released if copy_form_user fails. In order to prevent memory leak
in case of failure, the assignment to bounce_buf_ret is moved before the
error check. This way the allocated bounce_buf will be released by the
caller.

Fixes: 579db9d45cb4 ("virt: Add vboxguest VMMDEV communication code")
Signed-off-by: Navid Emamdoost <navid.emamdoost@xxxxxxxxx>
---
 drivers/virt/vboxguest/vboxguest_utils.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/virt/vboxguest/vboxguest_utils.c b/drivers/virt/vboxguest/vboxguest_utils.c
index 75fd140b02ff..43c391626a00 100644
--- a/drivers/virt/vboxguest/vboxguest_utils.c
+++ b/drivers/virt/vboxguest/vboxguest_utils.c
@@ -220,6 +220,8 @@ static int hgcm_call_preprocess_linaddr(
 	if (!bounce_buf)
 		return -ENOMEM;
 
+	*bounce_buf_ret = bounce_buf;
+
 	if (copy_in) {
 		ret = copy_from_user(bounce_buf, (void __user *)buf, len);
 		if (ret)
@@ -228,7 +230,6 @@ static int hgcm_call_preprocess_linaddr(
 		memset(bounce_buf, 0, len);
 	}
 
-	*bounce_buf_ret = bounce_buf;
 	hgcm_call_add_pagelist_size(bounce_buf, len, extra);
 	return 0;
 }
-- 
2.17.1