[bug report] Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode

[Dan Carpenter <dan.carpenter@oracle.com>]

Hello Luiz Augusto von Dentz,

The patch 15f02b910562: "Bluetooth: L2CAP: Add initial code for
Enhanced Credit Based Mode" from Mar 2, 2020, leads to the following
static checker warning:

	net/bluetooth/l2cap_core.c:6265 l2cap_ecred_reconf_rsp()
	warn: iterator 'chan->list.next' changed during iteration

net/bluetooth/l2cap_core.c
  6247  static inline int l2cap_ecred_reconf_rsp(struct l2cap_conn *conn,
  6248                                           struct l2cap_cmd_hdr *cmd, u16 cmd_len,
  6249                                           u8 *data)
  6250  {
  6251          struct l2cap_chan *chan;
  6252          struct l2cap_ecred_conn_rsp *rsp = (void *) data;
  6253          u16 result;
  6254  
  6255          if (cmd_len < sizeof(*rsp))
  6256                  return -EPROTO;
  6257  
  6258          result = __le16_to_cpu(rsp->result);
  6259  
  6260          BT_DBG("result 0x%4.4x", rsp->result);
  6261  
  6262          if (!result)
  6263                  return 0;
  6264  
  6265          list_for_each_entry(chan, &conn->chan_l, list) {
  6266                  if (chan->ident != cmd->ident)
  6267                          continue;
  6268  
  6269                  l2cap_chan_del(chan, ECONNRESET);
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This can call:

		list_del(&chan->list);

which will lead to an oops in the next iteration.

  6270          }
  6271  
  6272          return 0;
  6273  }

regards,
dan carpenter