2013-04-02 12:24:21

by Chan-yeol Park

Subject: [PATCH v4 1/3] Bluetooth: Fix hci-uart-h4 crash from incoming uart packet

This patch adds check HCI_UART_REGISTERED before reading uart data for
hci uart h4 driver. Uart data could be arrived when inside the
hci_uart_tty_ioctl function after calling test_and_set_bit for
HCI_UART_PROTO_SET but before the hci_uart_set_proto function has
returned.

Backtrace:
[<c05f27ec>] (hci_recv_stream_fragment+0x0/0x74) from [<c04126f4>] (h4_recv+0x18/0x40)
r7:eb1d4d1c r6:eb7683b0 r5:eae8e800 r4:0000000c
[<c04126dc>] (h4_recv+0x0/0x40) from [<c0411870>] (hci_uart_tty_receive+0x6c/0x94)
r5:eae8e800 r4:eb768380
[<c0411804>] (hci_uart_tty_receive+0x0/0x94) from [<c027be88>] (flush_to_ldisc+0x16c/0x17c)
r6:eae8e8d8 r5:eae8e800 r4:eae8e8c8
[<c027bd1c>] (flush_to_ldisc+0x0/0x17c) from [<c0050ae8>] (process_one_work+0x144/0x4d4)
[<c00509a4>] (process_one_work+0x0/0x4d4) from [<c0051208>] (worker_thread+0x180/0x370)
[<c0051088>] (worker_thread+0x0/0x370) from [<c005617c>] (kthread+0x90/0x9c)
[<c00560ec>] (kthread+0x0/0x9c) from [<c003a3a0>] (do_exit+0x0/0x7ec)

Signed-off-by: Chan-yeol Park <[email protected]>
---
drivers/bluetooth/hci_h4.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/bluetooth/hci_h4.c b/drivers/bluetooth/hci_h4.c
index c60623f..8ae9f1e 100644
--- a/drivers/bluetooth/hci_h4.c
+++ b/drivers/bluetooth/hci_h4.c
@@ -153,6 +153,9 @@ static int h4_recv(struct hci_uart *hu, void *data, int count)
{
int ret;

+ if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
+ return -EUNATCH;
+
ret = hci_recv_stream_fragment(hu->hdev, data, count);
if (ret < 0) {
BT_ERR("Frame Reassembly Failed");
--
1.7.10.4

2013-04-02 12:24:23

by Chan-yeol Park

Subject: [PATCH v4 3/3] Bluetooth: Remove trivial white space

Signed-off-by: Chan-yeol Park <[email protected]>
---
drivers/bluetooth/hci_ldisc.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index d710d8b..bc68a44 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -260,12 +260,12 @@ static int hci_uart_send_frame(struct sk_buff *skb)

/* ------ LDISC part ------ */
/* hci_uart_tty_open
- *
+ *
* Called when line discipline changed to HCI_UART.
*
* Arguments:
* tty pointer to tty info structure
- * Return Value:
+ * Return Value:
* 0 if success, otherwise error code
*/
static int hci_uart_tty_open(struct tty_struct *tty)
@@ -365,15 +365,15 @@ static void hci_uart_tty_wakeup(struct tty_struct *tty)
}

/* hci_uart_tty_receive()
- *
+ *
* Called by tty low level driver when receive data is
* available.
- *
+ *
* Arguments: tty pointer to tty isntance data
* data pointer to received data
* flags pointer to flags for data
* count count of received data in bytes
- *
+ *
* Return Value: None
*/
static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, char *flags, int count)
--
1.7.10.4

2013-04-02 12:24:22

by Chan-yeol Park

Subject: [PATCH v4 2/3] Bluetooth: Fix possible NULL dereference

This patch adds NULL check for hci uart ldisc driver because some of
hci uart drivers allow hci_uart_tty_receive function could be called
though hci uart driver is not registered properly.

Signed-off-by: Chan-yeol Park <[email protected]>
---
drivers/bluetooth/hci_ldisc.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index ed0fade..d710d8b 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -388,7 +388,10 @@ static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, char *f

spin_lock(&hu->rx_lock);
hu->proto->recv(hu, (void *) data, count);
- hu->hdev->stat.byte_rx += count;
+
+ if (hu->hdev)
+ hu->hdev->stat.byte_rx += count;
+
spin_unlock(&hu->rx_lock);

tty_unthrottle(tty);
--
1.7.10.4