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From:   Yang Yingliang <yangyingliang@huawei.com>
To:     <linux-kernel@vger.kernel.org>, <linux-scsi@vger.kernel.org>
CC:     <gregkh@linuxfoundation.org>, <rafael@kernel.org>,
        <jejb@linux.ibm.com>, <martin.petersen@oracle.com>
Subject: [PATCH] drivers: base: transport_class: fix resource leak when transport_add_device() fails
Date:   Thu, 10 Nov 2022 11:37:21 +0800
Message-ID: <20221110033721.11974-1-yangyingliang@huawei.com>
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The normal call sequence of using transport class is:

Add path:
transport_setup_device()
  transport_setup_classdev()  // call sas_host_setup() here
transport_add_device()	      // if fails, need call transport_destroy_device()
transport_configure_device()

Remove path:
transport_remove_device()
  transport_remove_classdev  // call sas_host_remove() here
transport_destroy_device()

If transport_add_device() fails, need call transport_destroy_device()
to free memory, but in this case, ->remove() is not called, and the
resources allocated in ->setup() are leaked. So fix these leaks by
calling ->remove() in transport_add_class_device() if it returns error.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
 drivers/base/transport_class.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/base/transport_class.c b/drivers/base/transport_class.c
index ccc86206e508..d0237db6236f 100644
--- a/drivers/base/transport_class.c
+++ b/drivers/base/transport_class.c
@@ -155,6 +155,7 @@ static int transport_add_class_device(struct attribute_container *cont,
 				      struct device *dev,
 				      struct device *classdev)
 {
+	struct transport_class *tclass = class_to_transport_class(cont->class);
 	int error = attribute_container_add_class_device(classdev);
 	struct transport_container *tcont = 
 		attribute_container_to_transport_container(cont);
@@ -162,6 +163,9 @@ static int transport_add_class_device(struct attribute_container *cont,
 	if (!error && tcont->statistics)
 		error = sysfs_create_group(&classdev->kobj, tcont->statistics);
 
+	if (error && tclass->remove)
+		tclass->remove(tcont, dev, classdev);
+
 	return error;
 }
 
-- 
2.25.1