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From:   Qinglang Miao <miaoqinglang@huawei.com>
To:     Lee Duncan <lduncan@suse.com>, Chris Leech <cleech@redhat.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>
CC:     <open-iscsi@googlegroups.com>, <linux-scsi@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>,
        Qinglang Miao <miaoqinglang@huawei.com>
Subject: [PATCH] scsi: iscsi: fix inappropriate use of put_device
Date:   Fri, 20 Nov 2020 15:48:52 +0800
Message-ID: <20201120074852.31658-1-miaoqinglang@huawei.com>
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Precedence: bulk

kfree(conn) is called inside put_device(&conn->dev) so that
another one would cause use-after-free. Besides, device_unregister
should be used here rather than put_device.

Fixes: f3c893e3dbb5 ("scsi: iscsi: Fail session and connection on transport registration failure")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
---
 drivers/scsi/scsi_transport_iscsi.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 2eb3e4f93..2e68c0a87 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -2313,7 +2313,9 @@ iscsi_create_conn(struct iscsi_cls_session *session, int dd_size, uint32_t cid)
 	return conn;
 
 release_conn_ref:
-	put_device(&conn->dev);
+	device_unregister(&conn->dev);
+	put_device(&session->dev);
+	return NULL;
 release_parent_ref:
 	put_device(&session->dev);
 free_conn:
-- 
2.23.0