Re: [PATCH v2] gpio: wcd934x: Fix shift-out-of-bounds error

[Bjorn Andersson]

On Wed 10 Mar 11:43 CST 2021, Srinivas Kandagatla wrote:

> bit-mask for pins 0 to 4 is BIT(0) to BIT(4) however we ended up with BIT(n - 1)
> which is not right, and this was caught by below usban check
> 
> UBSAN: shift-out-of-bounds in drivers/gpio/gpio-wcd934x.c:34:14
> 
> Fixes: 59c324683400 ("gpio: wcd934x: Add support to wcd934x gpio controller")
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>

Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>

Regards,
Bjorn

> ---
> changes since v1:
> 	- removed unnecessary dump stack from log
> 
>  drivers/gpio/gpio-wcd934x.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpio/gpio-wcd934x.c b/drivers/gpio/gpio-wcd934x.c
> index 1cbce5990855..97e6caedf1f3 100644
> --- a/drivers/gpio/gpio-wcd934x.c
> +++ b/drivers/gpio/gpio-wcd934x.c
> @@ -7,7 +7,7 @@
>  #include <linux/slab.h>
>  #include <linux/of_device.h>
>  
> -#define WCD_PIN_MASK(p) BIT(p - 1)
> +#define WCD_PIN_MASK(p) BIT(p)
>  #define WCD_REG_DIR_CTL_OFFSET 0x42
>  #define WCD_REG_VAL_CTL_OFFSET 0x43
>  #define WCD934X_NPINS		5
> -- 
> 2.21.0
>