Commit 8b36aa5a authored Dec 20, 2021 by Lixiaokeng Committed by Greg Kroah-Hartman Jan 11, 2022

scsi: libiscsi: Fix UAF in iscsi_conn_get_param()/iscsi_conn_teardown()

[ Upstream commit 1b8d0300a3e9f216ae4901bab886db7299899ec6 ]

|- iscsi_if_destroy_conn            |-dev_attr_show
 |-iscsi_conn_teardown
  |-spin_lock_bh                     |-iscsi_sw_tcp_conn_get_param

  |-kfree(conn->persistent_address)   |-iscsi_conn_get_param
  |-kfree(conn->local_ipaddr)
                                       ==>|-read persistent_address
                                       ==>|-read local_ipaddr
  |-spin_unlock_bh

When iscsi_conn_teardown() and iscsi_conn_get_param() happen in parallel, a
UAF may be triggered.

Link: https://lore.kernel.org/r/046ec8a0-ce95-d3fc-3235-666a7c65b224@huawei.com


Reported-by: Lu Tixiong <lutianxiong@huawei.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Lixiaokeng <lixiaokeng@huawei.com>
Signed-off-by: Linfeilong <linfeilong@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 6a3ffcc9

drivers/scsi/libiscsi.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -2948,6 +2948,8 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
		{
		struct iscsi_conn *conn = cls_conn->dd_data;
		struct iscsi_session *session = conn->session;
		char *tmp_persistent_address = conn->persistent_address;
		char *tmp_local_ipaddr = conn->local_ipaddr;

		del_timer_sync(&conn->transport_timer);

		@@ -2969,8 +2971,6 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
		spin_lock_bh(&session->frwd_lock);
		free_pages((unsigned long) conn->data,
		get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
		kfree(conn->persistent_address);
		kfree(conn->local_ipaddr);
		/* regular RX path uses back_lock */
		spin_lock_bh(&session->back_lock);
		kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
		@@ -2982,6 +2982,8 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
		mutex_unlock(&session->eh_mutex);

		iscsi_destroy_conn(cls_conn);
		kfree(tmp_persistent_address);
		kfree(tmp_local_ipaddr);
		}
		EXPORT_SYMBOL_GPL(iscsi_conn_teardown);