diff options
| author | Markus Burri <markus.burri@mt.com> | 2025-05-08 15:06:07 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-07-24 08:56:28 +0200 |
| commit | 6eea9f7648ddb9e4903735a1f77cf196c957aa38 (patch) | |
| tree | 93b874bb310c8db1181787b138afdc033db68d21 | |
| parent | 404b1d0fe0c6096578e5b545629f342124ee37a3 (diff) | |
iio: backend: fix out-of-bound write
commit da9374819eb3885636934c1006d450c3cb1a02ed upstream.
The buffer is set to 80 character. If a caller write more characters,
count is truncated to the max available space in "simple_write_to_buffer".
But afterwards a string terminator is written to the buffer at offset count
without boundary check. The zero termination is written OUT-OF-BOUND.
Add a check that the given buffer is smaller then the buffer to prevent.
Fixes: 035b4989211d ("iio: backend: make sure to NULL terminate stack buffer")
Signed-off-by: Markus Burri <markus.burri@mt.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Link: https://patch.msgid.link/20250508130612.82270-2-markus.burri@mt.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/iio/industrialio-backend.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/iio/industrialio-backend.c b/drivers/iio/industrialio-backend.c index 42e0ee683ef6..a3abcdeb6281 100644 --- a/drivers/iio/industrialio-backend.c +++ b/drivers/iio/industrialio-backend.c @@ -155,11 +155,14 @@ static ssize_t iio_backend_debugfs_write_reg(struct file *file, ssize_t rc; int ret; + if (count >= sizeof(buf)) + return -ENOSPC; + rc = simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, userbuf, count); if (rc < 0) return rc; - buf[count] = '\0'; + buf[rc] = '\0'; ret = sscanf(buf, "%i %i", &back->cached_reg_addr, &val); |