]> git.baikalelectronics.ru Git - kernel.git/commit
Bluetooth: hci_ldisc: Postpone HCI_UART_PROTO_READY bit set in hci_uart_set_proto()
authorKefeng Wang <wangkefeng.wang@huawei.com>
Sat, 23 Feb 2019 04:33:27 +0000 (12:33 +0800)
committerMarcel Holtmann <marcel@holtmann.org>
Tue, 26 Feb 2019 08:55:39 +0000 (09:55 +0100)
commit912841ca8ba29171ed6ff3beedbce8eb0f108ba8
tree9c50a376fe9717111aedcb6156c5e3aa32c4f19c
parent6a2abb96077d1fdcd55fdbe034cb4396fe417514
Bluetooth: hci_ldisc: Postpone HCI_UART_PROTO_READY bit set in hci_uart_set_proto()

task A:                                task B:
hci_uart_set_proto                     flush_to_ldisc
 - p->open(hu) -> h5_open  //alloc h5  - receive_buf
 - set_bit HCI_UART_PROTO_READY         - tty_port_default_receive_buf
 - hci_uart_register_dev                 - tty_ldisc_receive_buf
                                          - hci_uart_tty_receive
           - test_bit HCI_UART_PROTO_READY
            - h5_recv
 - clear_bit HCI_UART_PROTO_READY             while() {
 - p->open(hu) -> h5_close //free h5
              - h5_rx_3wire_hdr
               - h5_reset()  //use-after-free
                                              }

It could use ioctl to set hci uart proto, but there is
a use-after-free issue when hci_uart_register_dev() fail in
hci_uart_set_proto(), see stack above, fix this by setting
HCI_UART_PROTO_READY bit only when hci_uart_register_dev()
return success.

Reported-by: syzbot+899a33dc0fa0dbaf06a6@syzkaller.appspotmail.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Jeremy Cline <jcline@redhat.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
drivers/bluetooth/hci_ldisc.c