ACK: [Xenial][SRU][CVE-2019-10207][PATCH v2] Bluetooth: hci_uart: check for missing tty operations
Stefan Bader
stefan.bader at canonical.com
Mon Aug 26 13:57:25 UTC 2019
On 13.08.19 19:26, Connor Kuehl wrote:
> From: Vladis Dronov <vdronov at redhat.com>
>
> CVE-2019-10207
>
> 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=1b42faa2848963564a5b1b7f8c837ea7b55ffa50
> Reported-by: syzbot+79337b501d6aa974d0f6 at syzkaller.appspotmail.com
> Cc: stable at vger.kernel.org # v2.6.36+
> 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 at redhat.com>
> Signed-off-by: Marcel Holtmann <marcel at holtmann.org>
> Reviewed-by: Yu-Chen, Cho <acho at suse.com>
> Tested-by: Yu-Chen, Cho <acho at suse.com>
> Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
> (backported from commit b36a1552d7319bbfd5cf7f08726c23c5c66d4f73)
> [ Connor Kuehl: drivers/bluetooth/hci_mrvl.c does not exist in Xenial,
> so that hunk was dropped. The qca_open() function had a very minor
> merge conflict but that's just because the kzalloc invocation used
> GFP_KERNEL in the patch but Xenial uses GFP_ATOMIC. The check on the
> 'serdev' data member was also dropped from hci_uart_has_flow_control()
> because it doesn't exist in Xenial and there is no reason to backport
> the serdev commit(s) since this fix has no functional dependency on
> serdev (none of its functions are called). ]
> Signed-off-by: Connor Kuehl <connor.kuehl at canonical.com>
Acked-by: Stefan Bader <stefan.bader at canonical.com>
> ---
> v1 -> v2:
> * Dropped the commit that introduced serdev which let me:
> * Drop the if statement checking for the serdev data member on
> the hci_uart structure
>
> drivers/bluetooth/hci_ath.c | 3 +++
> drivers/bluetooth/hci_bcm.c | 3 +++
> drivers/bluetooth/hci_intel.c | 3 +++
> drivers/bluetooth/hci_ldisc.c | 9 +++++++++
> drivers/bluetooth/hci_qca.c | 3 +++
> drivers/bluetooth/hci_uart.h | 1 +
> 6 files changed, 22 insertions(+)
>
> diff --git a/drivers/bluetooth/hci_ath.c b/drivers/bluetooth/hci_ath.c
> index d776dfd51478..16f2131687e5 100644
> --- a/drivers/bluetooth/hci_ath.c
> +++ b/drivers/bluetooth/hci_ath.c
> @@ -101,6 +101,9 @@ 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;
> diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c
> index f9b569ef3dd7..20a1b4d1fd09 100644
> --- a/drivers/bluetooth/hci_bcm.c
> +++ b/drivers/bluetooth/hci_bcm.c
> @@ -279,6 +279,9 @@ static int bcm_open(struct hci_uart *hu)
>
> bt_dev_dbg(hu->hdev, "hu %p", hu);
>
> + if (!hci_uart_has_flow_control(hu))
> + return -EOPNOTSUPP;
> +
> bcm = kzalloc(sizeof(*bcm), GFP_KERNEL);
> if (!bcm)
> return -ENOMEM;
> diff --git a/drivers/bluetooth/hci_intel.c b/drivers/bluetooth/hci_intel.c
> index f40a86960fde..772c91d843ff 100644
> --- a/drivers/bluetooth/hci_intel.c
> +++ b/drivers/bluetooth/hci_intel.c
> @@ -407,6 +407,9 @@ static int intel_open(struct hci_uart *hu)
>
> BT_DBG("hu %p", hu);
>
> + if (!hci_uart_has_flow_control(hu))
> + return -EOPNOTSUPP;
> +
> intel = kzalloc(sizeof(*intel), GFP_KERNEL);
> if (!intel)
> return -ENOMEM;
> diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
> index 96bcec5598c2..d5db2332eb6f 100644
> --- a/drivers/bluetooth/hci_ldisc.c
> +++ b/drivers/bluetooth/hci_ldisc.c
> @@ -257,6 +257,15 @@ static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
> 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;
> +}
> +
> /* Flow control or un-flow control the device */
> void hci_uart_set_flow_control(struct hci_uart *hu, bool enable)
> {
> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
> index ecfb9ed2cff6..6b5b9ae6e809 100644
> --- a/drivers/bluetooth/hci_qca.c
> +++ b/drivers/bluetooth/hci_qca.c
> @@ -390,6 +390,9 @@ static int qca_open(struct hci_uart *hu)
>
> BT_DBG("hu %p qca_open", hu);
>
> + if (!hci_uart_has_flow_control(hu))
> + return -EOPNOTSUPP;
> +
> qca = kzalloc(sizeof(struct qca_data), GFP_ATOMIC);
> if (!qca)
> return -ENOMEM;
> diff --git a/drivers/bluetooth/hci_uart.h b/drivers/bluetooth/hci_uart.h
> index 82c92f1b65b4..ce00c02eb63f 100644
> --- a/drivers/bluetooth/hci_uart.h
> +++ b/drivers/bluetooth/hci_uart.h
> @@ -105,6 +105,7 @@ int hci_uart_tx_wakeup(struct hci_uart *hu);
> int hci_uart_init_ready(struct hci_uart *hu);
> void hci_uart_init_tty(struct hci_uart *hu);
> void hci_uart_set_baudrate(struct hci_uart *hu, unsigned int speed);
> +bool hci_uart_has_flow_control(struct hci_uart *hu);
> void hci_uart_set_flow_control(struct hci_uart *hu, bool enable);
> void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed,
> unsigned int oper_speed);
>
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