6.11-stable review patch. If anyone has any objections, please let me know.
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From: Lad Prabhakar prabhakar.mahadev-lad.rj@bp.renesas.com
[ Upstream commit 7b99b5ab885993bff010ebcd93be5e511c56e28a ]
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@b... Signed-off-by: Bartosz Golaszewski bartosz.golaszewski@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpio/gpiolib.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 3a9668cc100df..148bcfbf98e02 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -115,12 +115,12 @@ 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)