From 9d1894cd197e297c9ced5393fde6416324b7706d Mon Sep 17 00:00:00 2001 From: Matt Ranostay Date: Wed, 24 Aug 2016 23:44:49 -0700 Subject: [PATCH] iio: chemical: vz89x: prevent corrupted buffer from being read Signed-off-by: Matt Ranostay Signed-off-by: Jonathan Cameron --- drivers/iio/chemical/vz89x.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/iio/chemical/vz89x.c b/drivers/iio/chemical/vz89x.c index 289d2919deea..cd3870ead3fd 100644 --- a/drivers/iio/chemical/vz89x.c +++ b/drivers/iio/chemical/vz89x.c @@ -55,6 +55,7 @@ struct vz89x_data { struct mutex lock; int (*xfer)(struct vz89x_data *data, u8 cmd); + bool is_valid; unsigned long last_update; u8 buffer[VZ89TE_REG_MEASUREMENT_RD_SIZE]; }; @@ -229,7 +230,10 @@ static int vz89x_get_measurement(struct vz89x_data *data) /* sensor can only be polled once a second max per datasheet */ if (!time_after(jiffies, data->last_update + HZ)) - return 0; + return data->is_valid ? 0 : -EAGAIN; + + data->is_valid = false; + data->last_update = jiffies; ret = data->xfer(data, chip->cmd); if (ret < 0) @@ -239,7 +243,7 @@ static int vz89x_get_measurement(struct vz89x_data *data) if (ret) return -EAGAIN; - data->last_update = jiffies; + data->is_valid = true; return 0; } -- 2.45.2