diff options
| author | Kefeng Wang <wangkefeng.wang@huawei.com> | 2019-02-23 12:33:27 +0800 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2019-09-23 21:12:17 +0100 |
| commit | a79897227b81d588130813e83084b836733cb146 (patch) | |
| tree | e85fe9e57723307055c415d7e6493e616a0504a9 | |
| parent | 16adebe264399fc1e8a78296426442b050ea0f54 (diff) | |
Bluetooth: hci_ldisc: Postpone HCI_UART_PROTO_READY bit set in hci_uart_set_proto()
commit 56897b217a1d0a91c9920cb418d6b3fe922f590a upstream.
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>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -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 d1f95075c23b..d90b3d04ef31 100644 --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -477,15 +477,14 @@ static int hci_uart_set_proto(struct hci_uart *hu, int id) return err; 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); p->close(hu); return err; } + set_bit(HCI_UART_PROTO_READY, &hu->flags); return 0; } |