diff options
| author | Markus Burri <markus.burri@mt.com> | 2025-05-09 17:04:59 +0200 |
|---|---|---|
| committer | Bartosz Golaszewski <bartosz.golaszewski@linaro.org> | 2025-05-13 12:59:30 +0200 |
| commit | 7118be7c6072f40391923543fdd1563b8d56377c (patch) | |
| tree | af0dfe22dca3854801be64bc05f2f0b346e03e0a /drivers/gpio | |
| parent | 3e38f946062b4845961ab86b726651b4457b2af8 (diff) | |
gpio: virtuser: fix potential out-of-bound write
If the caller wrote more characters, count is truncated to the max
available space in "simple_write_to_buffer". Check that the input
size does not exceed the buffer size. Write a zero termination
afterwards.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202505091754.285hHbr2-lkp@intel.com/
Signed-off-by: Markus Burri <markus.burri@mt.com>
Link: https://lore.kernel.org/r/20250509150459.115489-1-markus.burri@mt.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | drivers/gpio/gpio-virtuser.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/gpio/gpio-virtuser.c b/drivers/gpio/gpio-virtuser.c index 13407fd4f0eb..eab6726953b4 100644 --- a/drivers/gpio/gpio-virtuser.c +++ b/drivers/gpio/gpio-virtuser.c @@ -401,10 +401,15 @@ static ssize_t gpio_virtuser_direction_do_write(struct file *file, char buf[32], *trimmed; int ret, dir, val = 0; - ret = simple_write_to_buffer(buf, sizeof(buf), ppos, user_buf, count); + if (count >= sizeof(buf)) + return -EINVAL; + + ret = simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, user_buf, count); if (ret < 0) return ret; + buf[ret] = '\0'; + trimmed = strim(buf); if (strcmp(trimmed, "input") == 0) { @@ -623,12 +628,15 @@ static ssize_t gpio_virtuser_consumer_write(struct file *file, char buf[GPIO_VIRTUSER_NAME_BUF_LEN + 2]; int ret; + if (count >= sizeof(buf)) + return -EINVAL; + ret = simple_write_to_buffer(buf, GPIO_VIRTUSER_NAME_BUF_LEN, ppos, user_buf, count); if (ret < 0) return ret; - buf[strlen(buf) - 1] = '\0'; + buf[ret] = '\0'; ret = gpiod_set_consumer_name(data->ad.desc, buf); if (ret) |