scsi: fcoe: fix null-ptr-deref Read in fc_release_transport

In fcoe_if_init, if fc_attach_transport(&fcoe_vport_fc_functions)
fails, need to free the previously memory and return fail, otherwise
will trigger null-ptr-deref Read in fc_release_transport.

fcoe_exit
  fcoe_if_exit
    fc_release_transport(fcoe_vport_scsi_transport)

Link: https://lore.kernel.org/r/1566279789-58207-1-git-send-email-zhengbin13@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c
index 8e217ab..813f26d 100644 (file)
--- a/drivers/scsi/fcoe/fcoe.c
+++ b/drivers/scsi/fcoe/fcoe.c
@@ -1250,15 +1250,21 @@ static int __init fcoe_if_init(void)
        /* attach to scsi transport */
        fcoe_nport_scsi_transport =
                fc_attach_transport(&fcoe_nport_fc_functions);
+       if (!fcoe_nport_scsi_transport)
+               goto err;
+
        fcoe_vport_scsi_transport =
                fc_attach_transport(&fcoe_vport_fc_functions);
-
-       if (!fcoe_nport_scsi_transport) {
-               printk(KERN_ERR "fcoe: Failed to attach to the FC transport\n");
-               return -ENODEV;
-       }
+       if (!fcoe_vport_scsi_transport)
+               goto err_vport;
 
        return 0;
+
+err_vport:
+       fc_release_transport(fcoe_nport_scsi_transport);
+err:
+       printk(KERN_ERR "fcoe: Failed to attach to the FC transport\n");
+       return -ENODEV;
 }
 
 /**