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 <[email protected]>
---
Not tested. Perhaps we should just remove this code since it has never
worked.
diff --git a/drivers/net/wireless/ralink/rt2x00/rt2500usb.c b/drivers/net/wireless/ralink/rt2x00/rt2500usb.c
index b50d873..d26018f 100644
--- 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,
> 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 <[email protected]>
> Acked-by: Stanislaw Gruszka <[email protected]>
Thanks, applied to wireless-drivers-next.git.
Kalle Valo
On Thu, Nov 26, 2015 at 02:55:23PM +0300, Dan Carpenter wrote:
> 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 <[email protected]>
Acked-by: Stanislaw Gruszka <[email protected]>
> ---
> Not tested. Perhaps we should just remove this code since it has never
> worked.
It is used for debugfs interface and I would like to keep it.
Stanislaw
On Thu, Nov 26, 2015 at 01:21:48PM +0100, walter harms wrote:
> > If the low 16 bits were initialized to zero then this code would only be
> > a problem on big endian systems.
> perhaps, cleaning *value would be sufficient ? Avoiding the need for a tmp var.
>
> *value = 0
> rt2500usb_register_read(rt2x00dev, offset, (u16 *)value);
>
Because if you initialize value then you still have a bug on big endian
systems.
regards,
dan carpenter
Am 26.11.2015 12:55, schrieb Dan Carpenter:
> 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 <[email protected]>
> ---
> Not tested. Perhaps we should just remove this code since it has never
> worked.
>
> diff --git a/drivers/net/wireless/ralink/rt2x00/rt2500usb.c b/drivers/net/wireless/ralink/rt2x00/rt2500usb.c
> index b50d873..d26018f 100644
> --- 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;
> }
>
perhaps, cleaning *value would be sufficient ? Avoiding the need for a tmp var.
*value = 0
rt2500usb_register_read(rt2x00dev, offset, (u16 *)value);
re,
wh
> static void _rt2500usb_register_write(struct rt2x00_dev *rt2x00dev,
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