hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IB18IH ------------------------------------------------ There could have race problem when concurrently online or offline the device. "adev->handler" could be set to NULL when calling hbmdev_check. Let's add lock to prevent the NULL pointer dereference. Fixes: f37b8c99659d ("soc: hisilicon: Setting the demand_offline in sysfs interface") Signed-off-by: Zhang Zekun <zhangzekun11@huawei.com> --- drivers/soc/hisilicon/hisi_hbmdev.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/soc/hisilicon/hisi_hbmdev.c b/drivers/soc/hisilicon/hisi_hbmdev.c index 4c7da1a0eb33..f09388a80009 100644 --- a/drivers/soc/hisilicon/hisi_hbmdev.c +++ b/drivers/soc/hisilicon/hisi_hbmdev.c @@ -85,9 +85,7 @@ static int hbmdev_check(struct acpi_device *adev, void *arg) if (!adev->handler) return 0; - acpi_scan_lock_acquire(); adev->handler->hotplug.demand_offline = true; - acpi_scan_lock_release(); } return 0; @@ -98,7 +96,9 @@ static int memdev_power_off(struct acpi_device *adev) acpi_handle handle = adev->handle; acpi_status status; + acpi_scan_lock_acquire(); acpi_dev_for_each_child(adev, hbmdev_check, NULL); + acpi_scan_lock_release(); status = acpi_evaluate_object(handle, "_OFF", NULL, NULL); if (ACPI_FAILURE(status)) { -- 2.17.1