Commit 2f6115ad authored by Bartosz Golaszewski's avatar Bartosz Golaszewski
Browse files

gpiolib: fix invalid pointer access in debugfs 



If the memory allocation in gpiolib_seq_start() fails, the s->private
field remains uninitialized and is later dereferenced without checking
in gpiolib_seq_stop(). Initialize s->private to NULL before calling
kzalloc() and check it before dereferencing it.

Fixes: e348544f ("gpio: protect the list of GPIO devices with SRCU")
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20251103141132.53471-1-brgl@bgdev.pl


Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
parent e5d527be

drivers/gpio/gpiolib.c

+7 −1
Original line number Diff line number Diff line
@@ -5296,6 +5296,8 @@ static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos) 
	struct gpio_device *gdev;

	loff_t index = *pos;



	s->private = NULL;



	priv = kzalloc(sizeof(*priv), GFP_KERNEL);

	if (!priv)

		return NULL;
@@ -5329,7 +5331,11 @@ static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos) 


static void gpiolib_seq_stop(struct seq_file *s, void *v)

{

	struct gpiolib_seq_priv *priv = s->private;

	struct gpiolib_seq_priv *priv;



	priv = s->private;

	if (!priv)

		return;



	srcu_read_unlock(&gpio_devices_srcu, priv->idx);

	kfree(priv);