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| author | Loic Poulain <loic.poulain@intel.com> | 2016-04-04 10:48:13 +0200 |
|---|---|---|
| committer | Marcel Holtmann <marcel@holtmann.org> | 2016-04-08 18:58:56 +0200 |
| commit | 84cb3df02aea4b00405521e67c4c67c2d525c364 (patch) | |
| tree | 4802172d6283adade1e8299ed851b4b2af8c14d2 | |
| parent | 1dbfc59a931495b2e7bdc4e85886162a0b03235b (diff) | |
| download | linux-84cb3df02aea4b00405521e67c4c67c2d525c364.tar.gz linux-84cb3df02aea4b00405521e67c4c67c2d525c364.tar.bz2 linux-84cb3df02aea4b00405521e67c4c67c2d525c364.zip | |
Bluetooth: hci_ldisc: Fix null pointer derefence in case of early data
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>
| -rw-r--r-- | drivers/bluetooth/hci_ldisc.c | 11 | ||||
| -rw-r--r-- | drivers/bluetooth/hci_uart.h | 1 |
2 files changed, 8 insertions, 4 deletions
diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c index c00168a5bb80..49b3e1e2d236 100644 --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -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; } diff --git a/drivers/bluetooth/hci_uart.h b/drivers/bluetooth/hci_uart.h index 4814ff08f427..839bad1d8152 100644 --- a/drivers/bluetooth/hci_uart.h +++ b/drivers/bluetooth/hci_uart.h @@ -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 |