If ret ends up negative, mutex_unlock is called repeatedly in an infinite loop, which of course is pretty nasty... Issue found by smatch: drivers/iio/inkern.c:751 iio_read_avail_channel_raw() error: double unlock 'mutex:&chan->indio_dev->info_exist_lock' Fixes: 00c5f80c2fad ("iio: inkern: add helpers to query available values from channels") Signed-off-by: Peter Rosin <peda@xxxxxxxxxx> --- drivers/iio/inkern.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) v1 -> v2 changes: - Be clear about that there is a real nasty issue and that it isn't only about avoiding some insignificant static checker issue. v1: https://lkml.org/lkml/2017/4/20/887 Cheers, peda diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c index 7a13535dc3e9..a3941bade6a7 100644 --- a/drivers/iio/inkern.c +++ b/drivers/iio/inkern.c @@ -750,11 +750,9 @@ int iio_read_avail_channel_raw(struct iio_channel *chan, err_unlock: mutex_unlock(&chan->indio_dev->info_exist_lock); - if (ret >= 0 && type != IIO_VAL_INT) { + if (ret >= 0 && type != IIO_VAL_INT) /* raw values are assumed to be IIO_VAL_INT */ ret = -EINVAL; - goto err_unlock; - } return ret; } -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html