[PATCH 4.6 038/203] gpio: make library immune to error pointers

Greg Kroah-Hartman
2016-07-25T21:41:03Z

From: Linus Walleij <linus.walleij@linaro.org>

commit c0a1ecb9f4e208f4b75d88fa9669748e3fd705ab upstream.

Most functions that take a GPIO descriptor in need to check the
descriptor for IS_ERR(). We do this mostly in the VALIDATE_DESC()
macro except for the gpiod_to_irq() function which needs special
handling.

Reported-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/gpio/gpiolib.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)

--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1345,8 +1345,12 @@ done:
#define VALIDATE_DESC(desc) do { \
if (!desc) \
return 0; \
+ if (IS_ERR(desc)) { \
+ pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
+ return PTR_ERR(desc); \
+ } \
if (!desc->gdev) { \
- pr_warn("%s: invalid GPIO\n", __func__); \
+ pr_warn("%s: invalid GPIO (no device)\n", __func__); \
return -EINVAL; \
} \
if ( !desc->gdev->chip ) { \
@@ -1358,8 +1362,12 @@ done:
#define VALIDATE_DESC_VOID(desc) do { \
if (!desc) \
return; \
+ if (IS_ERR(desc)) { \
+ pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
+ return; \
+ } \
if (!desc->gdev) { \
- pr_warn("%s: invalid GPIO\n", __func__); \
+ pr_warn("%s: invalid GPIO (no device)\n", __func__); \
return; \
} \
if (!desc->gdev->chip) { \
@@ -2011,7 +2019,7 @@ int gpiod_to_irq(const struct gpio_desc
* requires this function to not return zero on an invalid descriptor
* but rather a negative error number.
*/
- if (!desc || !desc->gdev || !desc->gdev->chip)
+ if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
return -EINVAL;

chip = desc->gdev->chip;