pinctrl: samsung: Validate alias coming from DT

Driver uses alias from Device Tree as an index of pin controller data
array.  In case of a wrong DTB or an out-of-tree DTB, the alias could be
outside of this data array leading to out-of-bounds access.

Depending on binary and memory layout, this could be handled properly
(showing error like "samsung-pinctrl 3860000.pinctrl: driver data not
available") or could lead to exceptions.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: <stable@vger.kernel.org>
Fixes: 30574f0db1b1 ("pinctrl: add samsung pinctrl and gpiolib driver")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 12 insertions, 2 deletions

diff --git a/drivers/pinctrl/samsung/pinctrl-exynos-arm64.c b/drivers/pinctrl/samsung/pinctrl-exynos-arm64.c
index fc8f7833bec0..71c9d1d9f345 100644
--- a/drivers/pinctrl/samsung/pinctrl-exynos-arm64.c
+++ b/drivers/pinctrl/samsung/pinctrl-exynos-arm64.c
@@ -175,7 +175,7 @@ static const struct samsung_retention_data exynos5433_fsys_retention_data __init
  * Samsung pinctrl driver data for Exynos5433 SoC. Exynos5433 SoC includes
  * ten gpio/pin-mux/pinconfig controllers.
  */
-const struct samsung_pin_ctrl exynos5433_pin_ctrl[] __initconst = {
+static const struct samsung_pin_ctrl exynos5433_pin_ctrl[] __initconst = {
 	{
 		/* pin-controller instance 0 data */
 		.pin_banks	= exynos5433_pin_banks0,
@@ -260,6 +260,11 @@ const struct samsung_pin_ctrl exynos5433_pin_ctrl[] __initconst = {
 	},
 };
 
+const struct samsung_pinctrl_of_match_data exynos5433_of_data __initconst = {
+	.ctrl		= exynos5433_pin_ctrl,
+	.num_ctrl	= ARRAY_SIZE(exynos5433_pin_ctrl),
+};
+
 /* pin banks of exynos7 pin-controller - ALIVE */
 static const struct samsung_pin_bank_data exynos7_pin_banks0[] __initconst = {
 	EXYNOS_PIN_BANK_EINTW(8, 0x000, "gpa0", 0x00),
@@ -339,7 +344,7 @@ static const struct samsung_pin_bank_data exynos7_pin_banks9[] __initconst = {
 	EXYNOS_PIN_BANK_EINTG(4, 0x020, "gpz1", 0x04),
 };
 
-const struct samsung_pin_ctrl exynos7_pin_ctrl[] __initconst = {
+static const struct samsung_pin_ctrl exynos7_pin_ctrl[] __initconst = {
 	{
 		/* pin-controller instance 0 Alive data */
 		.pin_banks	= exynos7_pin_banks0,
@@ -392,3 +397,8 @@ const struct samsung_pin_ctrl exynos7_pin_ctrl[] __initconst = {
 		.eint_gpio_init = exynos_eint_gpio_init,
 	},
 };
+
+const struct samsung_pinctrl_of_match_data exynos7_of_data __initconst = {
+	.ctrl		= exynos7_pin_ctrl,
+	.num_ctrl	= ARRAY_SIZE(exynos7_pin_ctrl),
+};