[PATCH 4.7 042/141] i40iw: Do not set self-referencing pointer to NULL after kfree

[Greg Kroah-Hartman]

4.7-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Mustafa Ismail <mustafa.ismail@xxxxxxxxx>

commit 7eaf8313b1cfe93417a22bdc3f7380cac2a3dc6d upstream.

In i40iw_free_virt_mem(), do not set mem->va to NULL
after freeing it as mem->va is a self-referencing pointer
to mem.

Fixes: 4e9042e647ff ("i40iw: add hw and utils files")

Reported-by: Stefan Assmann <sassmann@xxxxxxxxxx>
Signed-off-by: Mustafa Ismail <mustafa.ismail@xxxxxxxxx>
Signed-off-by: Shiraz Saleem <shiraz.saleem@xxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/infiniband/hw/i40iw/i40iw_utils.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/infiniband/hw/i40iw/i40iw_utils.c
+++ b/drivers/infiniband/hw/i40iw/i40iw_utils.c
@@ -673,8 +673,11 @@ enum i40iw_status_code i40iw_free_virt_m
 {
 	if (!mem)
 		return I40IW_ERR_PARAM;
+	/*
+	 * mem->va points to the parent of mem, so both mem and mem->va
+	 * can not be touched once mem->va is freed
+	 */
 	kfree(mem->va);
-	mem->va = NULL;
 	return 0;
 }