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authorBartosz Golaszewski <bartosz.golaszewski@linaro.org>2025-11-03 15:11:32 +0100
committerBartosz Golaszewski <bartosz.golaszewski@linaro.org>2025-11-03 16:11:01 +0100
commit2f6115ad8864cf3f48598f26c74c7c8e5c391919 (patch)
tree932f2f8f4417e0f14cd9214b0387caf79af13587
parente5d527be7e6984882306b49c067f1fec18920735 (diff)
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: e348544f7994 ("gpio: protect the list of GPIO devices with SRCU") Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20251103141132.53471-1-brgl@bgdev.pl Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
-rw-r--r--drivers/gpio/gpiolib.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 9952e412da50..cd8800ba5825 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -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);