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Non-zero ppos values aren't going to work at all. Check for that at the start of the function and return -EINVAL. Fixes: cdf01e0809a4 ("iio: backend: add debugFs interface") Signed-off-by: Dan Carpenter --- drivers/iio/industrialio-backend.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iio/industrialio-backend.c b/drivers/iio/industrialio-backend.c index 138ebebc9c0d..4763e224ebc6 100644 --- a/drivers/iio/industrialio-backend.c +++ b/drivers/iio/industrialio-backend.c @@ -156,7 +156,7 @@ static ssize_t iio_backend_debugfs_write_reg(struct file *file, ssize_t rc; int ret; - if (count >= sizeof(buf)) + if (*ppos != 0 || count >= sizeof(buf)) return -ENOSPC; rc = simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, userbuf, count); -- 2.53.0