diff options
| author | Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> | 2024-10-03 14:13:51 +0100 |
|---|---|---|
| committer | Bartosz Golaszewski <bartosz.golaszewski@linaro.org> | 2024-10-03 20:51:47 +0200 |
| commit | 7b99b5ab885993bff010ebcd93be5e511c56e28a (patch) | |
| tree | 1869d60c88daa01144bcb408a570266bfb2e1fe1 | |
| parent | 5a431e50e9d4189800be1607eef9deaf95959fc3 (diff) | |
gpiolib: Fix potential NULL pointer dereference in gpiod_get_label()
In `gpiod_get_label()`, it is possible that `srcu_dereference_check()` may
return a NULL pointer, leading to a scenario where `label->str` is accessed
without verifying if `label` itself is NULL.
This patch adds a proper NULL check for `label` before accessing
`label->str`. The check for `label->str != NULL` is removed because
`label->str` can never be NULL if `label` is not NULL.
This fixes the issue where the label name was being printed as `(efault)`
when dumping the sysfs GPIO file when `label == NULL`.
Fixes: 5a646e03e956 ("gpiolib: Return label, if set, for IRQ only line")
Fixes: a86d27693066 ("gpiolib: fix the speed of descriptor label setting with SRCU")
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20241003131351.472015-1-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
| -rw-r--r-- | drivers/gpio/gpiolib.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index c6afbf434366..d5952ab7752c 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -114,12 +114,12 @@ const char *gpiod_get_label(struct gpio_desc *desc) srcu_read_lock_held(&desc->gdev->desc_srcu)); if (test_bit(FLAG_USED_AS_IRQ, &flags)) - return label->str ?: "interrupt"; + return label ? label->str : "interrupt"; if (!test_bit(FLAG_REQUESTED, &flags)) return NULL; - return label->str; + return label ? label->str : NULL; } static void desc_free_label(struct rcu_head *rh) |