From: Dan Carpenter Date: Mon, 25 May 2026 07:16:11 +0000 (+0300) Subject: iio: backend: fix uninitialized data in debugfs X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a6e8b14a4897d0b6df9744f33d0a30e6b92368eb;p=thirdparty%2Flinux.git iio: backend: fix uninitialized data in debugfs If the *ppos value is non-zero then simple_write_to_buffer() will not initialize the start of the buf[] buffer. Non-zero ppos values aren't going to work at all. Check for that at the start of the function and return -ENOSPC. Fixes: cdf01e0809a4 ("iio: backend: add debugFs interface") Signed-off-by: Dan Carpenter Cc: Signed-off-by: Jonathan Cameron --- diff --git a/drivers/iio/industrialio-backend.c b/drivers/iio/industrialio-backend.c index 10e689f49441..cd697fbeae47 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);