Input: mtk-pmic-keys - fix possible null pointer dereference

In mtk_pmic_keys_probe, the regs parameter is only set if the button is
parsed in the device tree. However, on hardware where the button is left
floating, that node will most likely be removed not to enable that
input. In that case the code will try to dereference a null pointer.

Let's use the regs struct instead as it is defined for all supported
platforms. Note that it is ok setting the key reg even if that latter is
disabled as the interrupt won't be enabled anyway.

Fixes: b581acb49aec ("Input: mtk-pmic-keys - transfer per-key bit in mtk_pmic_keys_regs")
Signed-off-by: Gary Bisson <bisson.gary@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/keyboard/mtk-pmic-keys.c b/drivers/input/keyboard/mtk-pmic-keys.c
index 5ad6be9141603ad1e1bf8cb1dcab7ec6e54d2335..061d48350df661dd26832b307e1460ee8b8fd535 100644 (file)
--- a/drivers/input/keyboard/mtk-pmic-keys.c
+++ b/drivers/input/keyboard/mtk-pmic-keys.c
@@ -147,8 +147,8 @@ static void mtk_pmic_keys_lp_reset_setup(struct mtk_pmic_keys *keys,
        u32 value, mask;
        int error;
 
-       kregs_home = keys->keys[MTK_PMIC_HOMEKEY_INDEX].regs;
-       kregs_pwr = keys->keys[MTK_PMIC_PWRKEY_INDEX].regs;
+       kregs_home = &regs->keys_regs[MTK_PMIC_HOMEKEY_INDEX];
+       kregs_pwr = &regs->keys_regs[MTK_PMIC_PWRKEY_INDEX];
 
        error = of_property_read_u32(keys->dev->of_node, "power-off-time-sec",
                                     &long_press_debounce);