From: Dan Carpenter <error27@gmail.com>
To: "Nuno Sá" <nuno.sa@analog.com>
Cc: Jonathan Cameron <jic23@kernel.org>,
David Lechner <dlechner@baylibre.com>,
Andy Shevchenko <andy@kernel.org>,
linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org,
kernel-janitors@vger.kernel.org
Subject: [PATCH] iio: core: fix uninitialized data in debugfs
Date: Mon, 25 May 2026 10:16:27 +0300 [thread overview]
Message-ID: <ahP3S9nOYN3pG-Fp@stanley.mountain> (raw)
If *ppos is non-zero then simple_write_to_buffer() will not initialize
the start of buf[]. Non zero values for *ppos aren't going to work
anyway. Test for them at the start of the function and return -EINVAL.
Fixes: 6d5dd486c715 ("iio: core: make use of simple_write_to_buffer()")
Signed-off-by: Dan Carpenter <error27@gmail.com>
---
The original copy_from_user() code was better:
https://staticthinking.wordpress.com/2026/05/23/simple_write_to_buffer-is-complicated/
---
drivers/iio/industrialio-core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index bd6f4f9f4533..1308a534582b 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -419,7 +419,7 @@ static ssize_t iio_debugfs_write_reg(struct file *file,
char buf[80];
int ret;
- if (count >= sizeof(buf))
+ if (*ppos != 0 || count >= sizeof(buf))
return -EINVAL;
ret = simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, userbuf,
--
2.53.0
next reply other threads:[~2026-05-25 7:16 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-25 7:16 Dan Carpenter [this message]
2026-05-25 13:17 ` [PATCH] iio: core: fix uninitialized data in debugfs Maxwell Doose
2026-05-25 16:12 ` Dan Carpenter
2026-05-25 20:08 ` Maxwell Doose
2026-05-26 18:21 ` Jonathan Cameron
2026-06-04 7:31 ` Andy Shevchenko
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