From 16285a0931869baa618b1f5d304e1e9d090470a8 Mon Sep 17 00:00:00 2001 From: Markus Burri Date: Thu, 8 May 2025 15:06:09 +0200 Subject: [PATCH] iio: fix potential out-of-bound write The buffer is set to 20 characters. If a caller write more characters, count is truncated to the max available space in "simple_write_to_buffer". To protect from OoB access, check that the input size fit into buffer and add a zero terminator after copy to the end of the copied data. Fixes: 6d5dd486c715 iio: core: make use of simple_write_to_buffer() Signed-off-by: Markus Burri Link: https://patch.msgid.link/20250508130612.82270-4-markus.burri@mt.com Signed-off-by: Jonathan Cameron --- drivers/iio/industrialio-core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c index 178e99b111deb..5ffda104d4b29 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -411,12 +411,15 @@ static ssize_t iio_debugfs_write_reg(struct file *file, char buf[80]; int ret; + if (count >= sizeof(buf)) + return -EINVAL; + ret = simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, userbuf, count); if (ret < 0) return ret; - buf[count] = '\0'; + buf[ret] = '\0'; ret = sscanf(buf, "%i %i", ®, &val); -- 2.47.2