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>
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 5607fe8..cb314e3 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -2986,6 +2986,8 @@
{
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);
@@ -3007,8 +3009,6 @@
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,
@@ -3020,6 +3020,8 @@
mutex_unlock(&session->eh_mutex);
iscsi_destroy_conn(cls_conn);
+ kfree(tmp_persistent_address);
+ kfree(tmp_local_ipaddr);
}
EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
