This is a note to let you know that I've just added the patch titled
pinctrl: renesas: rzg2l: Fix NULL pointer dereference in rzg2l_dt_subnode_to_map()
to the 6.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pinctrl-renesas-rzg2l-fix-null-pointer-dereference-i.patch
and it can be found in the queue-6.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 8041a043d7086d43441e8c3647102c25bc1a7b45
Author: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
Date: Tue Aug 15 14:15:56 2023 +0100
pinctrl: renesas: rzg2l: Fix NULL pointer dereference in rzg2l_dt_subnode_to_map()
[ Upstream commit 661efa2284bbc2338da0424e219603f034072c74 ]
Fix the below random NULL pointer crash during boot by serializing
pinctrl group and function creation/remove calls in
rzg2l_dt_subnode_to_map() with mutex lock.
Crash log:
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
rzg2l_dt_subnode_to_map+0x314/0x44c
rzg2l_dt_node_to_map+0x164/0x194
pinctrl_dt_to_map+0x218/0x37c
create_pinctrl+0x70/0x3d8
While at it, add comments for bitmap_lock and lock.
Fixes: c4c4637eb57f ("pinctrl: renesas: Add RZ/G2L pin and gpio controller driver")
Tested-by: Chris Paterson <Chris.Paterson2@xxxxxxxxxxx>
Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Link: https://lore.kernel.org/r/20230815131558.33787-2-biju.das.jz@xxxxxxxxxxxxxx
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/pinctrl/renesas/pinctrl-rzg2l.c b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
index b53d26167da52..6e8a76556e238 100644
--- a/drivers/pinctrl/renesas/pinctrl-rzg2l.c
+++ b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
@@ -11,6 +11,7 @@
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/seq_file.h>
@@ -149,10 +150,11 @@ struct rzg2l_pinctrl {
struct gpio_chip gpio_chip;
struct pinctrl_gpio_range gpio_range;
DECLARE_BITMAP(tint_slot, RZG2L_TINT_MAX_INTERRUPT);
- spinlock_t bitmap_lock;
+ spinlock_t bitmap_lock; /* protect tint_slot bitmap */
unsigned int hwirq[RZG2L_TINT_MAX_INTERRUPT];
- spinlock_t lock;
+ spinlock_t lock; /* lock read/write registers */
+ struct mutex mutex; /* serialize adding groups and functions */
};
static const unsigned int iolh_groupa_mA[] = { 2, 4, 8, 12 };
@@ -362,11 +364,13 @@ static int rzg2l_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;
}
/*
@@ -380,6 +384,8 @@ static int rzg2l_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;
@@ -391,6 +397,8 @@ static int rzg2l_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);
@@ -1509,6 +1517,7 @@ static int rzg2l_pinctrl_probe(struct platform_device *pdev)
spin_lock_init(&pctrl->lock);
spin_lock_init(&pctrl->bitmap_lock);
+ mutex_init(&pctrl->mutex);
platform_set_drvdata(pdev, pctrl);
