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 check for the missing tty
operations to the protocols which use them.
This fixes CVE-2019-10207.
Link: https://syzkaller.appspot.com/bug?id=1b42faa2848963564a5b1b7f8c837ea7b55ffa50
Reported-by: [email protected]
Cc: [email protected] # 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 <[email protected]>
---
drivers/bluetooth/hci_ath.c | 3 +++
drivers/bluetooth/hci_bcm.c | 5 +++++
drivers/bluetooth/hci_intel.c | 3 +++
drivers/bluetooth/hci_mrvl.c | 3 +++
drivers/bluetooth/hci_qca.c | 4 ++++
5 files changed, 18 insertions(+)
diff --git a/drivers/bluetooth/hci_ath.c b/drivers/bluetooth/hci_ath.c
index a55be205b91a..99df8a13e47e 100644
--- a/drivers/bluetooth/hci_ath.c
+++ b/drivers/bluetooth/hci_ath.c
@@ -98,6 +98,9 @@ static int ath_open(struct hci_uart *hu)
BT_DBG("hu %p", hu);
+ if (!hu->tty->driver->ops->tiocmget || !hu->tty->driver->ops->tiocmset)
+ return -ENOTSUPP;
+
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 8905ad2edde7..8c3e09cc341c 100644
--- a/drivers/bluetooth/hci_bcm.c
+++ b/drivers/bluetooth/hci_bcm.c
@@ -406,6 +406,11 @@ static int bcm_open(struct hci_uart *hu)
bt_dev_dbg(hu->hdev, "hu %p", hu);
+#ifdef CONFIG_PM
+ if (!hu->tty->driver->ops->tiocmget || !hu->tty->driver->ops->tiocmset)
+ return -ENOTSUPP;
+#endif
+
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 207bae5e0d46..a314882a1cac 100644
--- a/drivers/bluetooth/hci_intel.c
+++ b/drivers/bluetooth/hci_intel.c
@@ -391,6 +391,9 @@ static int intel_open(struct hci_uart *hu)
BT_DBG("hu %p", hu);
+ if (!hu->tty->driver->ops->tiocmget || !hu->tty->driver->ops->tiocmset)
+ return -ENOTSUPP;
+
intel = kzalloc(sizeof(*intel), GFP_KERNEL);
if (!intel)
return -ENOMEM;
diff --git a/drivers/bluetooth/hci_mrvl.c b/drivers/bluetooth/hci_mrvl.c
index f98e5cc343b2..4ee27c8d8679 100644
--- a/drivers/bluetooth/hci_mrvl.c
+++ b/drivers/bluetooth/hci_mrvl.c
@@ -59,6 +59,9 @@ static int mrvl_open(struct hci_uart *hu)
BT_DBG("hu %p", hu);
+ if (!hu->tty->driver->ops->tiocmget || !hu->tty->driver->ops->tiocmset)
+ return -ENOTSUPP;
+
mrvl = kzalloc(sizeof(*mrvl), GFP_KERNEL);
if (!mrvl)
return -ENOMEM;
diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index 9a5c9c1f9484..a65c202e8995 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -28,6 +28,7 @@
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/serdev.h>
+#include <linux/tty.h>
#include <asm/unaligned.h>
#include <net/bluetooth/bluetooth.h>
@@ -473,6 +474,9 @@ static int qca_open(struct hci_uart *hu)
BT_DBG("hu %p qca_open", hu);
+ if (!hu->tty->driver->ops->tiocmget || !hu->tty->driver->ops->tiocmset)
+ return -ENOTSUPP;
+
qca = kzalloc(sizeof(struct qca_data), GFP_KERNEL);
if (!qca)
return -ENOMEM;
--
2.20.1
Hi Vladis,
> 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 check for the missing tty
> operations to the protocols which use them.
>
> This fixes CVE-2019-10207.
>
> Link: https://syzkaller.appspot.com/bug?id=1b42faa2848963564a5b1b7f8c837ea7b55ffa50
> Reported-by: [email protected]
> Cc: [email protected] # 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 <[email protected]>
> ---
> drivers/bluetooth/hci_ath.c | 3 +++
> drivers/bluetooth/hci_bcm.c | 5 +++++
> drivers/bluetooth/hci_intel.c | 3 +++
> drivers/bluetooth/hci_mrvl.c | 3 +++
> drivers/bluetooth/hci_qca.c | 4 ++++
> 5 files changed, 18 insertions(+)
>
> diff --git a/drivers/bluetooth/hci_ath.c b/drivers/bluetooth/hci_ath.c
> index a55be205b91a..99df8a13e47e 100644
> --- a/drivers/bluetooth/hci_ath.c
> +++ b/drivers/bluetooth/hci_ath.c
> @@ -98,6 +98,9 @@ static int ath_open(struct hci_uart *hu)
>
> BT_DBG("hu %p", hu);
>
> + if (!hu->tty->driver->ops->tiocmget || !hu->tty->driver->ops->tiocmset)
> + return -ENOTSUPP;
> +
> 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 8905ad2edde7..8c3e09cc341c 100644
> --- a/drivers/bluetooth/hci_bcm.c
> +++ b/drivers/bluetooth/hci_bcm.c
> @@ -406,6 +406,11 @@ static int bcm_open(struct hci_uart *hu)
>
> bt_dev_dbg(hu->hdev, "hu %p", hu);
>
> +#ifdef CONFIG_PM
> + if (!hu->tty->driver->ops->tiocmget || !hu->tty->driver->ops->tiocmset)
> + return -ENOTSUPP;
> +#endif
> +
why is this one hidden behind CONFIG_PM? The general baud rate changes are independent of runtime power management support.
And I would introduce a bool hci_uart_has_tiocm_support(struct hci_uart *) helper.
Regards
Marcel
Hi Vladis,
>> why is this one hidden behind CONFIG_PM? The general baud rate changes are
>> independent of runtime power management support.
>
> hci_bcm calls hci_uart_set_flow_control() only from functions hidden behind
> #ifdef-CONFIG_PM (surely this can change in the future), and so without
> CONFIG_PM set it cannot hit the bug (as of now). So I've hidden the check
> for tiocm[gs]et() behind #ifdef-CONFIG_PM too.
>
> If you tell me it is better to remove this #ifdef, I'll remove it.
just remove it since I think that is a coincidence actually. And I think you also need to add a check in hci_h5.c since that got Realtek support, it should also use flow control or baud rate settings.
>> And I would introduce a bool hci_uart_has_tiocm_support(struct hci_uart *)
>> helper.
>
> Great, I will add it to the v2 fix. I guess a good place for it is hci_ldisc.c,
> near hci_uart_set_flow_control(), isn't it?
Sounds good.
Regards
Marcel