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Bluetooth: hci_ldisc: Fix null pointer derefence in case of early data

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HCI_UART_PROTO_SET flag is set before hci_uart_set_proto call. If we
receive data from tty layer during this procedure, proto pointer may
not be assigned yet, leading to null pointer dereference in rx method
hci_uart_tty_receive.

This patch fixes this issue by introducing HCI_UART_PROTO_READY flag in
order to avoid any proto operation before proto opening and assignment.

Signed-off-by: Loic Poulain <loic.poulain@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This commit is contained in:
Loic Poulain 2016-04-04 10:48:13 +02:00 committed by Marcel Holtmann
parent 1dbfc59a93
commit 84cb3df02a
2 changed files with 8 additions and 4 deletions
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11
drivers/bluetooth/hci_ldisc.c
View File

@ -227,7 +227,7 @@ static int hci_uart_flush(struct hci_dev *hdev)
tty_ldisc_flush(tty);
tty_driver_flush_buffer(tty);
if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
hu->proto->flush(hu);
return 0;
@ -492,7 +492,7 @@ static void hci_uart_tty_close(struct tty_struct *tty)
cancel_work_sync(&hu->write_work);
if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {
if (test_and_clear_bit(HCI_UART_PROTO_READY, &hu->flags)) {
if (hdev) {
if (test_bit(HCI_UART_REGISTERED, &hu->flags))
hci_unregister_dev(hdev);
@ -500,6 +500,7 @@ static void hci_uart_tty_close(struct tty_struct *tty)
}
hu->proto->close(hu);
}
clear_bit(HCI_UART_PROTO_SET, &hu->flags);
kfree(hu);
}
@ -526,7 +527,7 @@ static void hci_uart_tty_wakeup(struct tty_struct *tty)
if (tty != hu->tty)
return;
if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
hci_uart_tx_wakeup(hu);
}
@ -550,7 +551,7 @@ static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
if (!hu || tty != hu->tty)
return;
if (!test_bit(HCI_UART_PROTO_SET, &hu->flags))
if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
return;
/* It does not need a lock here as it is already protected by a mutex in
@ -638,9 +639,11 @@ 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;
}

1
drivers/bluetooth/hci_uart.h
View File

@ -95,6 +95,7 @@ struct hci_uart {
/* HCI_UART proto flag bits */
#define HCI_UART_PROTO_SET 0
#define HCI_UART_REGISTERED 1
#define HCI_UART_PROTO_READY 2
/* TX states */
#define HCI_UART_SENDING 1