From: Vladis Dronov <vdronov@redhat.com>
To: marcel@holtmann.org
Cc: bgodavar@codeaurora.org, frederic.danis@linux.intel.com,
johan.hedberg@gmail.com, linux-bluetooth@vger.kernel.org,
linux-kernel@vger.kernel.org, loic.poulain@intel.com,
suraj@atheros.com, syzkaller@googlegroups.com,
vdronov@redhat.com
Subject: [PATCH v3] Bluetooth: hci_uart: check for missing tty operations
Date: Mon, 29 Jul 2019 14:22:15 +0200 [thread overview]
Message-ID: <20190729122215.9948-1-vdronov@redhat.com> (raw)
In-Reply-To: <62A82405-46E2-4921-BA52-D1660FC2DDDB@holtmann.org>
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@syzkaller.appspotmail.com
Cc: stable@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@redhat.com>
---
out-of-commit-message-note:
it is possible that a HCI UART protocol uses serial device's
operations and not a tty ones. i made hci_uart_has_flow_control() to
check this also, hence the name. serial device's code checks if
the needed operations are present itself.
i believe, hci_h5 does not need this check, as it uses serial device
functions only (as of now):
serdev_device_set_flow_control(h5->hu->serdev, false);
serdev_device_set_baudrate(h5->hu->serdev, 115200);
drivers/bluetooth/hci_ath.c | 3 +++
drivers/bluetooth/hci_bcm.c | 3 +++
drivers/bluetooth/hci_intel.c | 3 +++
drivers/bluetooth/hci_ldisc.c | 7 +++++++
drivers/bluetooth/hci_mrvl.c | 3 +++
drivers/bluetooth/hci_qca.c | 3 +++
drivers/bluetooth/hci_uart.h | 1 +
7 files changed, 23 insertions(+)
diff --git a/drivers/bluetooth/hci_ath.c b/drivers/bluetooth/hci_ath.c
index a55be205b91a..dbfe34664633 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 (!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 8905ad2edde7..ae2624fce913 100644
--- a/drivers/bluetooth/hci_bcm.c
+++ b/drivers/bluetooth/hci_bcm.c
@@ -406,6 +406,9 @@ 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 207bae5e0d46..31f25153087d 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 (!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 8950e07889fe..11049e2336f3 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -292,6 +292,13 @@ 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)
+{
+ return hu->serdev ||
+ (hu->tty->driver->ops->tiocmget && hu->tty->driver->ops->tiocmset);
+}
+
/* 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_mrvl.c b/drivers/bluetooth/hci_mrvl.c
index f98e5cc343b2..fbc3f7c3a5c7 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 (!hci_uart_has_flow_control(hu))
+ return -EOPNOTSUPP;
+
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..82a0a3691a63 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -473,6 +473,9 @@ 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_KERNEL);
if (!qca)
return -ENOMEM;
diff --git a/drivers/bluetooth/hci_uart.h b/drivers/bluetooth/hci_uart.h
index f11af3912ce6..6ab631101019 100644
--- a/drivers/bluetooth/hci_uart.h
+++ b/drivers/bluetooth/hci_uart.h
@@ -104,6 +104,7 @@ int hci_uart_wait_until_sent(struct hci_uart *hu);
int hci_uart_init_ready(struct hci_uart *hu);
void hci_uart_init_work(struct work_struct *work);
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);
--
2.20.1
next prev parent reply other threads:[~2019-07-29 12:22 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-26 14:26 [PATCH v2] Bluetooth: hci_ldisc: check for missing tty operations Vladis Dronov
2019-07-26 21:48 ` Marcel Holtmann
2019-07-29 12:22 ` Vladis Dronov [this message]
2019-07-30 9:34 ` [PATCH v3] Bluetooth: hci_uart: " Marcel Holtmann
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