[PATCH 1/2] usbserial: Fixes use-after-free in serial_open().

[Luiz Fernando Capitulino]

 If the device is disconnected while serial_open() is executing and either
try_module_get() or the device specific open function fails, the kref_put()
call in the 'bailout_kref_put' label will free the memory pointed out by
'port'.

 The subsequent dereferences in the 'bailout_kref_put' label will be
invalid.

 The fix is just to assure kref_put() is called after any 'port' usage.

Signed-off-by: Luiz Fernando N. Capitulino <lcapitulino@xxxxxxxxxxxxxxx>

---

 drivers/usb/serial/usb-serial.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

4eaa6dcadd9df93d0297cdff45fe8a30169c7abe
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 071f86a..d9dceb4 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -225,9 +225,9 @@ static int serial_open (struct tty_struc
 bailout_module_put:
 	module_put(serial->type->driver.owner);
 bailout_kref_put:
-	kref_put(&serial->kref, destroy_serial);
 	port->open_count = 0;
 	mutex_unlock(&port->mutex);
+	kref_put(&serial->kref, destroy_serial);
 	return retval;
 }
 
-- 
1.3.1.ge5de



-- 
Luiz Fernando N. Capitulino
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/