We've had instances of drivers returning invalid values from gpio_chip
calbacks. In several cases these return values would be propagated to
user-space and confuse programs that only expect 0 or negative errnos
from ioctl()s. Let's sanitize the return values of callbacks and make
sure we don't allow anyone see invalid ones.
The first patch checks the return values of get_direction() in kernel
where needed and is a backportable fix.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
---
Bartosz Golaszewski (8):
gpiolib: check the return value of gpio_chip::get_direction()
gpiolib: sanitize the return value of gpio_chip::request()
gpiolib: sanitize the return value of gpio_chip::set_config()
gpiolib: sanitize the return value of gpio_chip::get()
gpiolib: sanitize the return value of gpio_chip::get_multiple()
gpiolib: sanitize the return value of gpio_chip::direction_output()
gpiolib: sanitize the return value of gpio_chip::direction_input()
gpiolib: sanitize the return value of gpio_chip::get_direction()
drivers/gpio/gpiolib.c | 144 +++++++++++++++++++++++++++++++++++---------
include/linux/gpio/driver.h | 6 +-
2 files changed, 120 insertions(+), 30 deletions(-)
---
base-commit: a13f6e0f405ed0d3bcfd37c692c7d7fa3c052154
change-id: 20241212-gpio-sanitize-retvals-f5f4e0d6f57d
Best regards,
--
Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
