From: Loic Poulain loic.poulain@intel.com
commit 84cb3df02aea4b00405521e67c4c67c2d525c364 upstream.
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 Cc: Ralph Siemsen ralph.siemsen@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/bluetooth/hci_ldisc.c | 11 +++++++---- drivers/bluetooth/hci_uart.h | 1 + 2 files changed, 8 insertions(+), 4 deletions(-)
--- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -227,7 +227,7 @@ static int hci_uart_flush(struct hci_dev 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; @@ -506,7 +506,7 @@ static void hci_uart_tty_close(struct tt
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); @@ -514,6 +514,7 @@ static void hci_uart_tty_close(struct tt } hu->proto->close(hu); } + clear_bit(HCI_UART_PROTO_SET, &hu->flags);
kfree(hu); } @@ -540,7 +541,7 @@ static void hci_uart_tty_wakeup(struct t 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); }
@@ -564,7 +565,7 @@ static void hci_uart_tty_receive(struct 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 @@ -652,9 +653,11 @@ static int hci_uart_set_proto(struct hci 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; } --- a/drivers/bluetooth/hci_uart.h +++ b/drivers/bluetooth/hci_uart.h @@ -94,6 +94,7 @@ 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