3.16.72-rc1 review patch. If anyone has any objections, please let me know.
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From: Vladis Dronov vdronov@redhat.com
commit b36a1552d7319bbfd5cf7f08726c23c5c66d4f73 upstream.
Certain ttys operations (pty_unix98_ops) lack tiocmget() and tiocmset() functions which are called by the certain HCI UART protocols (hci_ath, hci_bcm, hci_intel, hci_mrvl, hci_qca) via hci_uart_set_flow_control() or directly. This leads to an execution at NULL and can be triggered by an unprivileged user. Fix this by adding a helper function and a check for the missing tty operations in the protocols code.
This fixes CVE-2019-10207. The Fixes: lines list commits where calls to tiocm[gs]et() or hci_uart_set_flow_control() were added to the HCI UART protocols.
Link: https://syzkaller.appspot.com/bug?id=1b42faa2848963564a5b1b7f8c837ea7b55ffa5... Reported-by: syzbot+79337b501d6aa974d0f6@syzkaller.appspotmail.com Fixes: b3190df62861 ("Bluetooth: Support for Atheros AR300x serial chip") Fixes: 118612fb9165 ("Bluetooth: hci_bcm: Add suspend/resume PM functions") Fixes: ff2895592f0f ("Bluetooth: hci_intel: Add Intel baudrate configuration support") Fixes: 162f812f23ba ("Bluetooth: hci_uart: Add Marvell support") Fixes: fa9ad876b8e0 ("Bluetooth: hci_qca: Add support for Qualcomm Bluetooth chip wcn3990") Signed-off-by: Vladis Dronov vdronov@redhat.com Signed-off-by: Marcel Holtmann marcel@holtmann.org Reviewed-by: Yu-Chen, Cho acho@suse.com Tested-by: Yu-Chen, Cho acho@suse.com Signed-off-by: Linus Torvalds torvalds@linux-foundation.org [bwh: Backported to 3.16: - Only hci_ath is affected - There is no serdev support] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- --- a/drivers/bluetooth/hci_ath.c +++ b/drivers/bluetooth/hci_ath.c @@ -112,6 +112,9 @@ static int ath_open(struct hci_uart *hu)
BT_DBG("hu %p", hu);
+ if (!hci_uart_has_flow_control(hu)) + return -EOPNOTSUPP; + ath = kzalloc(sizeof(*ath), GFP_KERNEL); if (!ath) return -ENOMEM; --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -261,6 +261,15 @@ static int hci_uart_send_frame(struct hc return 0; }
+/* Check the underlying device or tty has flow control support */ +bool hci_uart_has_flow_control(struct hci_uart *hu) +{ + if (hu->tty->driver->ops->tiocmget && hu->tty->driver->ops->tiocmset) + return true; + + return false; +} + /* ------ LDISC part ------ */ /* hci_uart_tty_open * --- a/drivers/bluetooth/hci_uart.h +++ b/drivers/bluetooth/hci_uart.h @@ -90,6 +90,7 @@ int hci_uart_register_proto(struct hci_u int hci_uart_unregister_proto(struct hci_uart_proto *p); int hci_uart_tx_wakeup(struct hci_uart *hu); int hci_uart_init_ready(struct hci_uart *hu); +bool hci_uart_has_flow_control(struct hci_uart *hu);
#ifdef CONFIG_BT_HCIUART_H4 int h4_init(void);