From 3c91c8f424d3e44c8645ab765a38773e58afb07d Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Mon, 3 Nov 2025 15:11:32 +0100 Subject: [PATCH] gpiolib: fix invalid pointer access in debugfs [ Upstream commit 2f6115ad8864cf3f48598f26c74c7c8e5c391919 ] 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: e348544f7994 ("gpio: protect the list of GPIO devices with SRCU") Reviewed-by: Linus Walleij Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20251103141132.53471-1-brgl@bgdev.pl Signed-off-by: Bartosz Golaszewski Signed-off-by: Sasha Levin --- drivers/gpio/gpiolib.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 74d54513730a7..4aa66d7b08598 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -5285,6 +5285,8 @@ 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; @@ -5318,7 +5320,11 @@ 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); -- 2.47.3