| Message ID | 20230710070745.5505-1-jlee@suse.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Bluetooth: hci_ldisc: check HCI_UART_PROTO_READY flag in HCIUARTGETPROTO | expand |
diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c index efdda2c3fce8..a76eb98c0047 100644 --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -770,7 +770,8 @@ static int hci_uart_tty_ioctl(struct tty_struct *tty, unsigned int cmd, break; case HCIUARTGETPROTO: - if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) + if (test_bit(HCI_UART_PROTO_SET, &hu->flags) && + test_bit(HCI_UART_PROTO_READY, &hu->flags)) err = hu->proto->id; else err = -EUNATCH;
This patch adds code to check HCI_UART_PROTO_READY flag before accessing hci_uart->proto. It fixs the race condition in hci_uart_tty_ioctl() between HCIUARTSETPROTO and HCIUARTGETPROTO. This issue bug found by Yu Hao and Weiteng Chen: BUG: general protection fault in hci_uart_tty_ioctl https://lore.kernel.org/all/CA+UBctC3p49aTgzbVgkSZ2+TQcqq4fPDO7yZitFT5uBPDeCO2g@mail.gmail.com/ The information of C reproducer can also reference here: https://lore.kernel.org/lkml/CA+UBctDPEvHdkHMwD340=n02rh+jNRJNNQ5LBZNA+Wm4Keh2ow@mail.gmail.com/T/ Reported-by: Weiteng Chen <wchen130@ucr.edu> Reported-by: Yu Hao <yhao016@ucr.edu> Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com> --- drivers/bluetooth/hci_ldisc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)