s390/dasd: fix memleak in path handling error case

If for whatever reason the dasd_eckd_check_characteristics() function
exits after at least some paths have their configuration data
allocated those data is never freed again. In the error case the
device->private pointer is set to NULL and dasd_eckd_uncheck_device()
will exit without freeing the path data because of this NULL pointer.

Fix by calling dasd_eckd_clear_conf_data() for error cases.

Also use dasd_eckd_clear_conf_data() in dasd_eckd_uncheck_device()
to avoid code duplication.

Reported-by: Qian Cai <cai@lca.pw>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index f5622f4a2ecfc822a68c1935652a237b12b26ac6..a28b9ff823780de364ba7e79d871a92c464bce49 100644 (file)
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -2074,7 +2074,7 @@ dasd_eckd_check_characteristics(struct dasd_device *device)
        dasd_free_block(device->block);
        device->block = NULL;
 out_err1:
-       kfree(private->conf_data);
+       dasd_eckd_clear_conf_data(device);
        kfree(device->private);
        device->private = NULL;
        return rc;
@@ -2083,7 +2083,6 @@ dasd_eckd_check_characteristics(struct dasd_device *device)
 static void dasd_eckd_uncheck_device(struct dasd_device *device)
 {
        struct dasd_eckd_private *private = device->private;
-       int i;
 
        if (!private)
                return;
@@ -2093,21 +2092,7 @@ static void dasd_eckd_uncheck_device(struct dasd_device *device)
        private->sneq = NULL;
        private->vdsneq = NULL;
        private->gneq = NULL;
-       private->conf_len = 0;
-       for (i = 0; i < 8; i++) {
-               kfree(device->path[i].conf_data);
-               if ((__u8 *)device->path[i].conf_data ==
-                   private->conf_data) {
-                       private->conf_data = NULL;
-                       private->conf_len = 0;
-               }
-               device->path[i].conf_data = NULL;
-               device->path[i].cssid = 0;
-               device->path[i].ssid = 0;
-               device->path[i].chpid = 0;
-       }
-       kfree(private->conf_data);
-       private->conf_data = NULL;
+       dasd_eckd_clear_conf_data(device);
 }
 
 static struct dasd_ccw_req *