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Really, non-zero values for *ppos aren't going to work at all. Check for that return -EINVAL at the start of the function. Fixes: 91581c4b3f29 ("gpio: virtuser: new virtual testing driver for the GPIO API") Signed-off-by: Dan Carpenter --- drivers/gpio/gpio-virtuser.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpio/gpio-virtuser.c b/drivers/gpio/gpio-virtuser.c index 128520d340d4..846f8688fec5 100644 --- a/drivers/gpio/gpio-virtuser.c +++ b/drivers/gpio/gpio-virtuser.c @@ -397,7 +397,7 @@ static ssize_t gpio_virtuser_direction_do_write(struct file *file, char buf[32], *trimmed; int ret, dir, val = 0; - if (count >= sizeof(buf)) + if (*ppos != 0 || count >= sizeof(buf)) return -EINVAL; ret = simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, user_buf, count); @@ -622,7 +622,7 @@ static ssize_t gpio_virtuser_consumer_write(struct file *file, char buf[GPIO_VIRTUSER_NAME_BUF_LEN + 2]; int ret; - if (count >= sizeof(buf)) + if (*ppos != 0 || count >= sizeof(buf)) return -EINVAL; ret = simple_write_to_buffer(buf, GPIO_VIRTUSER_NAME_BUF_LEN, ppos, -- 2.53.0