From d70674eeaa5efdefb99928691161578ae0a80316 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 25 Oct 2016 17:55:04 +0200 Subject: [PATCH] iio: maxim_thermocouple: detect invalid storage size in read() 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 Signed-off-by: Jonathan Cameron (cherry picked from commit 32cb7d27e65df9daa7cee8f1fdf7b259f214bee2) Signed-off-by: Greg Kroah-Hartman --- 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) -- 2.20.1