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authorKefeng Wang <wangkefeng.wang@huawei.com>2019-02-23 05:33:27 +0100
committerMarcel Holtmann <marcel@holtmann.org>2019-02-26 09:55:39 +0100
commit56897b217a1d0a91c9920cb418d6b3fe922f590a (patch)
tree9c50a376fe9717111aedcb6156c5e3aa32c4f19c
parentBluetooth: mgmt: Use struct_size() helper (diff)
downloadlinux-56897b217a1d0a91c9920cb418d6b3fe922f590a.tar.xz
linux-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.c3
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;
}