pinctrl: canaan: k230: Fix NULL pointer dereference when parsing devicetree

When probing the k230 pinctrl driver, the kernel triggers a NULL pointer
dereference. The crash trace showed:
[    0.732084] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000068
[    0.740737] ...
[    0.776296] epc : k230_pinctrl_probe+0x1be/0x4fc

In k230_pinctrl_parse_functions(), we attempt to retrieve the device
pointer via info->pctl_dev->dev, but info->pctl_dev is only initialized
after k230_pinctrl_parse_dt() completes.

At the time of DT parsing, info->pctl_dev is still NULL, leading to
the invalid dereference of info->pctl_dev->dev.

Use the already available device pointer from platform_device
instead of accessing through uninitialized pctl_dev.

Fixes: d94a32ac688f ("pinctrl: canaan: k230: Fix order of DT parse and pinctrl register")
Signed-off-by: Jiayu Du <jiayu.riscv@isrc.iscas.ac.cn>
Signed-off-by: Linus Walleij <linusw@kernel.org>

diff --git a/drivers/pinctrl/pinctrl-k230.c b/drivers/pinctrl/pinctrl-k230.c
index d716f23d837f7a70993a75346561ef0b1e07c3eb..20f7c0f70eb77c03ade0e15953fd391abdff7261 100644 (file)
--- a/drivers/pinctrl/pinctrl-k230.c
+++ b/drivers/pinctrl/pinctrl-k230.c
@@ -65,6 +65,7 @@ struct k230_pmx_func {
 };
 
 struct k230_pinctrl {
+       struct device           *dev;
        struct pinctrl_desc     pctl;
        struct pinctrl_dev      *pctl_dev;
        struct regmap           *regmap_base;
@@ -470,7 +471,7 @@ static int k230_pinctrl_parse_groups(struct device_node *np,
                                     struct k230_pinctrl *info,
                                     unsigned int index)
 {
-       struct device *dev = info->pctl_dev->dev;
+       struct device *dev = info->dev;
        const __be32 *list;
        int size, i, ret;
 
@@ -511,7 +512,7 @@ static int k230_pinctrl_parse_functions(struct device_node *np,
                                        struct k230_pinctrl *info,
                                        unsigned int index)
 {
-       struct device *dev = info->pctl_dev->dev;
+       struct device *dev = info->dev;
        struct k230_pmx_func *func;
        struct k230_pin_group *grp;
        static unsigned int idx, i;
@@ -596,6 +597,8 @@ static int k230_pinctrl_probe(struct platform_device *pdev)
        if (!info)
                return -ENOMEM;
 
+       info->dev = dev;
+
        pctl = &info->pctl;
 
        pctl->name      = "k230-pinctrl";