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USB: serial/keyspan_pda, fix potential tty NULL dereferences 

Make sure that we check the return value of tty_port_tty_get.
Sometimes it may return NULL and we later dereference that.

There are several places to check. For easier handling,
tty_port_tty_get is moved directly to the palce where needed in
keyspan_pda_rx_interrupt.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Jiri Slaby 2011-02-28 10:34:05 +01:00 committed by Greg Kroah-Hartman
parent 7adc14b14b
commit f7d7aedfcd
1 changed files with 8 additions and 7 deletions
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15
drivers/usb/serial/keyspan_pda.c
View File

@ -173,7 +173,8 @@ static void keyspan_pda_wakeup_write(struct work_struct *work)
container_of(work, struct keyspan_pda_private, wakeup_work); container_of(work, struct keyspan_pda_private, wakeup_work);
struct usb_serial_port *port = priv->port; struct usb_serial_port *port = priv->port;
struct tty_struct *tty = tty_port_tty_get(&port->port); struct tty_struct *tty = tty_port_tty_get(&port->port);
tty_wakeup(tty); if (tty)
tty_wakeup(tty);
tty_kref_put(tty); tty_kref_put(tty);
} }
@ -206,7 +207,7 @@ static void keyspan_pda_request_unthrottle(struct work_struct *work)
static void keyspan_pda_rx_interrupt(struct urb *urb) static void keyspan_pda_rx_interrupt(struct urb *urb)
{ {
struct usb_serial_port *port = urb->context; struct usb_serial_port *port = urb->context;
struct tty_struct *tty = tty_port_tty_get(&port->port); struct tty_struct *tty;
unsigned char *data = urb->transfer_buffer; unsigned char *data = urb->transfer_buffer;
int retval; int retval;
int status = urb->status; int status = urb->status;
@ -223,7 +224,7 @@ static void keyspan_pda_rx_interrupt(struct urb *urb)
/* this urb is terminated, clean up */ /* this urb is terminated, clean up */
dbg("%s - urb shutting down with status: %d", dbg("%s - urb shutting down with status: %d",
__func__, status); __func__, status);
goto out; return;
default: default:
dbg("%s - nonzero urb status received: %d", dbg("%s - nonzero urb status received: %d",
__func__, status); __func__, status);
@ -233,12 +234,14 @@ static void keyspan_pda_rx_interrupt(struct urb *urb)
/* see if the message is data or a status interrupt */ /* see if the message is data or a status interrupt */
switch (data[0]) { switch (data[0]) {
case 0: case 0:
/* rest of message is rx data */ tty = tty_port_tty_get(&port->port);
if (urb->actual_length) { /* rest of message is rx data */
if (tty && urb->actual_length) {
tty_insert_flip_string(tty, data + 1, tty_insert_flip_string(tty, data + 1,
urb->actual_length - 1); urb->actual_length - 1);
tty_flip_buffer_push(tty); tty_flip_buffer_push(tty);
} }
tty_kref_put(tty);
break; break;
case 1: case 1:
/* status interrupt */ /* status interrupt */
@ -265,8 +268,6 @@ exit:
dev_err(&port->dev, dev_err(&port->dev,
"%s - usb_submit_urb failed with result %d", "%s - usb_submit_urb failed with result %d",
__func__, retval); __func__, retval);
out:
tty_kref_put(tty);
} }