[PATCH] [ACPI] fan_core: Add error handling in fan_set_state_acpi4

[Haoran Liu]

This patch introduces error handling for the acpi_driver_data
call within the fan_set_state_acpi4 function in
drivers/acpi/fan_core.c. Previously, the function did not account
for potential null returns from acpi_driver_data, which could
lead to instability if encountered.

Signed-off-by: Haoran Liu <liuhaoran14@xxxxxxx>
---
 drivers/acpi/fan_core.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/acpi/fan_core.c b/drivers/acpi/fan_core.c
index 9dccbae9e8ea..f2553a47a705 100644
--- a/drivers/acpi/fan_core.c
+++ b/drivers/acpi/fan_core.c
@@ -154,6 +154,12 @@ static int fan_set_state_acpi4(struct acpi_device *device, unsigned long state)
 	u64 value = state;
 	int max_state;
 
+	if (!fan) {
+		pr_err("%s: No ACPI fan data "
+			"associated with the device\n", __func__);
+		return -ENODEV;
+	}
+
 	if (fan->fif.fine_grain_ctrl)
 		max_state = 100 / fan->fif.step_size;
 	else
-- 
2.17.1