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| author |   Kefeng Wang <wangkefeng.wang@huawei.com> | 2019-02-23 12:33:27 +0800 |
|---|---|---|
| committer |   Marcel Holtmann <marcel@holtmann.org> | 2019-02-26 09:55:39 +0100 |
| commit | 56897b217a1d0a91c9920cb418d6b3fe922f590a (patch) | |
| tree | 9c50a376fe9717111aedcb6156c5e3aa32c4f19c | |
| parent | Bluetooth: mgmt: Use struct_size() helper (diff) | |
| download | linux-dev-56897b217a1d0a91c9920cb418d6b3fe922f590a.tar.xz linux-dev-56897b217a1d0a91c9920cb418d6b3fe922f590a.zip | |
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>
| -rw-r--r-- | drivers/bluetooth/hci_ldisc.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c index 4918fefc4a6f..9562e72c1ae5 100644 --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -696,14 +696,13 @@ static int hci_uart_set_proto(struct hci_uart *hu, int id) return -EPROTONOSUPPORT; hu->proto = p; - set_bit(HCI_UART_PROTO_READY, &hu->flags); err = hci_uart_register_dev(hu); if (err) { - clear_bit(HCI_UART_PROTO_READY, &hu->flags); return err; } + set_bit(HCI_UART_PROTO_READY, &hu->flags); return 0; } |