Commit f982b9d5 authored by Biju Das's avatar Biju Das Committed by Geert Uytterhoeven
Browse files

pinctrl: renesas: rzv2m: Fix NULL pointer dereference in rzv2m_dt_subnode_to_map() 



Fix the below random NULL pointer crash during boot by serializing
pinctrl group and function creation/remove calls in
rzv2m_dt_subnode_to_map() with mutex lock.

Crash logs:
    pc : __pi_strcmp+0x20/0x140
    lr : pinmux_func_name_to_selector+0x68/0xa4
    Call trace:
    __pi_strcmp+0x20/0x140
    pinmux_generic_add_function+0x34/0xcc
    rzv2m_dt_subnode_to_map+0x2e4/0x418
    rzv2m_dt_node_to_map+0x15c/0x18c
    pinctrl_dt_to_map+0x218/0x37c
    create_pinctrl+0x70/0x3d8

While at it, add a comment for lock.

Fixes: 92a9b825 ("pinctrl: renesas: Add RZ/V2M pin and gpio controller driver")
Signed-off-by: default avatarBiju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230815131558.33787-3-biju.das.jz@bp.renesas.com


Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
parent 661efa22

drivers/pinctrl/renesas/pinctrl-rzv2m.c

+11 −2
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/gpio/driver.h>

#include <linux/io.h>

#include <linux/module.h>

#include <linux/mutex.h>

#include <linux/of_device.h>

#include <linux/spinlock.h>
@@ -123,7 +124,8 @@ struct rzv2m_pinctrl { 
	struct gpio_chip		gpio_chip;

	struct pinctrl_gpio_range	gpio_range;



	spinlock_t			lock;

	spinlock_t			lock; /* lock read/write registers */

	struct mutex			mutex; /* serialize adding groups and functions */

};



static const unsigned int drv_1_8V_group2_uA[] = { 1800, 3800, 7800, 11000 };
@@ -322,11 +324,13 @@ static int rzv2m_dt_subnode_to_map(struct pinctrl_dev *pctldev, 
		name = np->name;

	}



	mutex_lock(&pctrl->mutex);



	/* Register a single pin group listing all the pins we read from DT */

	gsel = pinctrl_generic_add_group(pctldev, name, pins, num_pinmux, NULL);

	if (gsel < 0) {

		ret = gsel;

		goto done;

		goto unlock;

	}



	/*
@@ -340,6 +344,8 @@ static int rzv2m_dt_subnode_to_map(struct pinctrl_dev *pctldev, 
		goto remove_group;

	}



	mutex_unlock(&pctrl->mutex);



	maps[idx].type = PIN_MAP_TYPE_MUX_GROUP;

	maps[idx].data.mux.group = name;

	maps[idx].data.mux.function = name;
@@ -351,6 +357,8 @@ static int rzv2m_dt_subnode_to_map(struct pinctrl_dev *pctldev, 


remove_group:

	pinctrl_generic_remove_group(pctldev, gsel);

unlock:

	mutex_unlock(&pctrl->mutex);

done:

	*index = idx;

	kfree(configs);
@@ -1071,6 +1079,7 @@ static int rzv2m_pinctrl_probe(struct platform_device *pdev) 
	}



	spin_lock_init(&pctrl->lock);

	mutex_init(&pctrl->mutex);



	platform_set_drvdata(pdev, pctrl);