rt2x00: type bug in _rt2500usb_register_read()

This code causes a static checker bug.

drivers/net/wireless/ralink/rt2x00/rt2500usb.c:232 _rt2500usb_register_read()
warn: passing casted pointer 'value' to 'rt2500usb_register_read()' 32 vs 16.

If the low 16 bits were initialized to zero then this code would only be
a problem on big endian systems.  But in this case this is case the low
16 bits are never initialized.  This is called from a function which is
created using a macro:

RT2X00DEBUGFS_OPS(csr, "0x%.8x\n", u32);

We end up copying uninitialized data to the user which is bogus and an
information leak.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

diff --git a/drivers/net/wireless/ralink/rt2x00/rt2500usb.c b/drivers/net/wireless/ralink/rt2x00/rt2500usb.c
index b50d873..d26018f 100644 (file)
--- a/drivers/net/wireless/ralink/rt2x00/rt2500usb.c
+++ b/drivers/net/wireless/ralink/rt2x00/rt2500usb.c
@@ -229,7 +229,10 @@ static void _rt2500usb_register_read(struct rt2x00_dev *rt2x00dev,
                                     const unsigned int offset,
                                     u32 *value)
 {
-       rt2500usb_register_read(rt2x00dev, offset, (u16 *)value);
+       u16 tmp;
+
+       rt2500usb_register_read(rt2x00dev, offset, &tmp);
+       *value = tmp;
 }
 
 static void _rt2500usb_register_write(struct rt2x00_dev *rt2x00dev,