qed: Prevent stack corruption on MFW interaction
Driver uses a union for copying data to & from management firmware
when interacting with it.
Problem is that the function always copies sizeof(union) while commit
2edbff8dcb5d ("qed: Learn resources from management firmware") is casting
a union elements which is of smaller size [24-byte instead of 88-bytes].
Also, the union contains some inappropriate elements which increase its
size [should have been 32-bytes]. While this shouldn't corrupt other
PF messages to the MFW [as management firmware enforces permissions so
that each PF is allowed to write only to its own mailbox] we fix this
here as well.
Fixes: 2edbff8dcb5d ("qed: Learn resources from management firmware")
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/qlogic/qed/qed_mcp.c b/drivers/net/ethernet/qlogic/qed/qed_mcp.c
index d8e499e..6dd3ce4 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_mcp.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_mcp.c
@@ -1697,19 +1697,27 @@ int qed_mcp_get_resc_info(struct qed_hwfn *p_hwfn,
u32 *p_mcp_resp, u32 *p_mcp_param)
{
struct qed_mcp_mb_params mb_params;
- union drv_union_data *p_union_data;
+ union drv_union_data union_data;
int rc;
memset(&mb_params, 0, sizeof(mb_params));
+ memset(&union_data, 0, sizeof(union_data));
mb_params.cmd = DRV_MSG_GET_RESOURCE_ALLOC_MSG;
mb_params.param = QED_RESC_ALLOC_VERSION;
- p_union_data = (union drv_union_data *)p_resc_info;
- mb_params.p_data_src = p_union_data;
- mb_params.p_data_dst = p_union_data;
+
+ /* Need to have a sufficient large struct, as the cmd_and_union
+ * is going to do memcpy from and to it.
+ */
+ memcpy(&union_data.resource, p_resc_info, sizeof(*p_resc_info));
+
+ mb_params.p_data_src = &union_data;
+ mb_params.p_data_dst = &union_data;
rc = qed_mcp_cmd_and_union(p_hwfn, p_ptt, &mb_params);
if (rc)
return rc;
+ /* Copy the data back */
+ memcpy(p_resc_info, &union_data.resource, sizeof(*p_resc_info));
*p_mcp_resp = mb_params.mcp_resp;
*p_mcp_param = mb_params.mcp_param;