From: Dinghao Liu <dinghao.liu@zju.edu.cn>
Date: Sat, 23 Sep 2023 10:37:23 +0000 (+0800)
Subject: scsi: zfcp: Fix a double put in zfcp_port_enqueue()
X-Git-Tag: v4.14.327~22
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=44d3ee21d8e076a62e5d88e3e796ef609d2d144d;p=thirdparty%2Fkernel%2Fstable.git

scsi: zfcp: Fix a double put in zfcp_port_enqueue()

commit b481f644d9174670b385c3a699617052cd2a79d3 upstream.

When device_register() fails, zfcp_port_release() will be called after
put_device(). As a result, zfcp_ccw_adapter_put() will be called twice: one
in zfcp_port_release() and one in the error path after device_register().
So the reference on the adapter object is doubly put, which may lead to a
premature free. Fix this by adjusting the error tag after
device_register().

Fixes: f3450c7b9172 ("[SCSI] zfcp: Replace local reference counting with common kref")
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Link: https://lore.kernel.org/r/20230923103723.10320-1-dinghao.liu@zju.edu.cn
Acked-by: Benjamin Block <bblock@linux.ibm.com>
Cc: stable@vger.kernel.org # v2.6.33+
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index fab02bd73d85b..843c5aa62933c 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -492,12 +492,12 @@ struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
 	if (port) {
 		put_device(&port->dev);
 		retval = -EEXIST;
-		goto err_out;
+		goto err_put;
 	}
 
 	port = kzalloc(sizeof(struct zfcp_port), GFP_KERNEL);
 	if (!port)
-		goto err_out;
+		goto err_put;
 
 	rwlock_init(&port->unit_list_lock);
 	INIT_LIST_HEAD(&port->unit_list);
@@ -520,7 +520,7 @@ struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
 
 	if (dev_set_name(&port->dev, "0x%016llx", (unsigned long long)wwpn)) {
 		kfree(port);
-		goto err_out;
+		goto err_put;
 	}
 	retval = -EINVAL;
 
@@ -537,8 +537,9 @@ struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
 
 	return port;
 
-err_out:
+err_put:
 	zfcp_ccw_adapter_put(adapter);
+err_out:
 	return ERR_PTR(retval);
 }