s390/dasd: fix double free in dasd_eckd_read_conf
The configuration data is stored per path and also the first valid
configuration data per device. When dasd_eckd_read_conf is called
again after a path got lost the device configuration data is cleared
but possibly not the per path configuration data. This might lead to a
double free when the lost path gets operational again.
Fix by clearing all per path configuration data when the first valid
configuration data is received and stored.
Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 30c2a80..e53b895a 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -1032,6 +1032,21 @@
return 0;
}
+static void dasd_eckd_clear_conf_data(struct dasd_device *device)
+{
+ struct dasd_eckd_private *private;
+ int i;
+
+ private = (struct dasd_eckd_private *) device->private;
+ private->conf_data = NULL;
+ private->conf_len = 0;
+ for (i = 0; i < 8; i++) {
+ kfree(private->path_conf_data[i]);
+ private->path_conf_data[i] = NULL;
+ }
+}
+
+
static int dasd_eckd_read_conf(struct dasd_device *device)
{
void *conf_data;
@@ -1068,19 +1083,10 @@
path_data->opm |= lpm;
continue; /* no error */
}
- pos = pathmask_to_pos(lpm);
- kfree(private->path_conf_data[pos]);
- if ((__u8 *)private->path_conf_data[pos] ==
- private->conf_data) {
- private->conf_data = NULL;
- private->conf_len = 0;
- conf_data_saved = 0;
- }
- private->path_conf_data[pos] =
- (struct dasd_conf_data *) conf_data;
/* save first valid configuration data */
if (!conf_data_saved) {
- kfree(private->conf_data);
+ /* initially clear previously stored conf_data */
+ dasd_eckd_clear_conf_data(device);
private->conf_data = conf_data;
private->conf_len = conf_len;
if (dasd_eckd_identify_conf_parts(private)) {
@@ -1089,6 +1095,10 @@
kfree(conf_data);
continue;
}
+ pos = pathmask_to_pos(lpm);
+ /* store per path conf_data */
+ private->path_conf_data[pos] =
+ (struct dasd_conf_data *) conf_data;
/*
* build device UID that other path data
* can be compared to it
@@ -1146,7 +1156,10 @@
path_data->cablepm |= lpm;
continue;
}
-
+ pos = pathmask_to_pos(lpm);
+ /* store per path conf_data */
+ private->path_conf_data[pos] =
+ (struct dasd_conf_data *) conf_data;
path_private.conf_data = NULL;
path_private.conf_len = 0;
}