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authorLad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>2024-10-03 15:13:51 +0200
committerBartosz Golaszewski <bartosz.golaszewski@linaro.org>2024-10-03 20:51:47 +0200
commit7b99b5ab885993bff010ebcd93be5e511c56e28a (patch)
tree1869d60c88daa01144bcb408a570266bfb2e1fe1
parentgpio: davinci: Fix condition for irqchip registration (diff)
downloadlinux-7b99b5ab885993bff010ebcd93be5e511c56e28a.tar.xz
linux-7b99b5ab885993bff010ebcd93be5e511c56e28a.zip
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.c4
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)