* [PATCH] iio: maxim_thermocouple: detect invalid storage size in read()
@ 2016-10-25 15:55 Arnd Bergmann
2016-10-25 16:29 ` Jonathan Cameron
0 siblings, 1 reply; 2+ messages in thread
From: Arnd Bergmann @ 2016-10-25 15:55 UTC (permalink / raw)
To: Jonathan Cameron
Cc: Arnd Bergmann, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Matt Ranostay, sayli karnik, Wei Yongjun,
linux-iio, linux-kernel
As found by gcc -Wmaybe-uninitialized, having a storage_bytes value other
than 2 or 4 will result in undefined behavior:
drivers/iio/temperature/maxim_thermocouple.c: In function 'maxim_thermocouple_read':
drivers/iio/temperature/maxim_thermocouple.c:141:5: error: 'ret' may be used uninitialized in this function [-Werror=maybe-uninitialized]
This probably cannot happen, but returning -EINVAL here is appropriate
and makes gcc happy and the code more robust.
Fixes: 231147ee77f3 ("iio: maxim_thermocouple: Align 16 bit big endian value of raw reads")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/iio/temperature/maxim_thermocouple.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/iio/temperature/maxim_thermocouple.c b/drivers/iio/temperature/maxim_thermocouple.c
index 066161a4bccd..f962f31a5eb2 100644
--- a/drivers/iio/temperature/maxim_thermocouple.c
+++ b/drivers/iio/temperature/maxim_thermocouple.c
@@ -136,6 +136,8 @@ static int maxim_thermocouple_read(struct maxim_thermocouple_data *data,
ret = spi_read(data->spi, (void *)&buf32, storage_bytes);
*val = be32_to_cpu(buf32);
break;
+ default:
+ ret = -EINVAL;
}
if (ret)
--
2.9.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] iio: maxim_thermocouple: detect invalid storage size in read()
2016-10-25 15:55 [PATCH] iio: maxim_thermocouple: detect invalid storage size in read() Arnd Bergmann
@ 2016-10-25 16:29 ` Jonathan Cameron
0 siblings, 0 replies; 2+ messages in thread
From: Jonathan Cameron @ 2016-10-25 16:29 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Hartmut Knaack, Lars-Peter Clausen, Peter Meerwald-Stadler,
Matt Ranostay, sayli karnik, Wei Yongjun, linux-iio,
linux-kernel
On 25/10/16 16:55, Arnd Bergmann wrote:
> As found by gcc -Wmaybe-uninitialized, having a storage_bytes value other
> than 2 or 4 will result in undefined behavior:
>
> drivers/iio/temperature/maxim_thermocouple.c: In function 'maxim_thermocouple_read':
> drivers/iio/temperature/maxim_thermocouple.c:141:5: error: 'ret' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>
> This probably cannot happen, but returning -EINVAL here is appropriate
> and makes gcc happy and the code more robust.
Agreed on all counts.
>
> Fixes: 231147ee77f3 ("iio: maxim_thermocouple: Align 16 bit big endian value of raw reads")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Applied to the togreg branch of iio.git. Initially pushed out as testing for the
autobuilders to play with it.
Thanks,
Jonathan
> ---
> drivers/iio/temperature/maxim_thermocouple.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/iio/temperature/maxim_thermocouple.c b/drivers/iio/temperature/maxim_thermocouple.c
> index 066161a4bccd..f962f31a5eb2 100644
> --- a/drivers/iio/temperature/maxim_thermocouple.c
> +++ b/drivers/iio/temperature/maxim_thermocouple.c
> @@ -136,6 +136,8 @@ static int maxim_thermocouple_read(struct maxim_thermocouple_data *data,
> ret = spi_read(data->spi, (void *)&buf32, storage_bytes);
> *val = be32_to_cpu(buf32);
> break;
> + default:
> + ret = -EINVAL;
> }
>
> if (ret)
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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