From ceeb1defbd59ef1585f32bb95d0498c7beeebd9b Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 26 Jun 2020 19:42:34 +0200 Subject: [PATCH] PCI: hotplug: ACPI: Fix context refcounting in acpiphp_grab_context() commit dae68d7fd4930315389117e9da35b763f12238f9 upstream. If context is not NULL in acpiphp_grab_context(), but the is_going_away flag is set for the device's parent, the reference counter of the context needs to be decremented before returning NULL or the context will never be freed, so make that happen. Fixes: edf5bf34d408 ("ACPI / dock: Use callback pointers from devices' ACPI hotplug contexts") Reported-by: Vasily Averin Cc: 3.15+ # 3.15+ Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman --- drivers/pci/hotplug/acpiphp_glue.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c index 711875afdd70..f2c1008e0f76 100644 --- a/drivers/pci/hotplug/acpiphp_glue.c +++ b/drivers/pci/hotplug/acpiphp_glue.c @@ -136,13 +136,21 @@ static struct acpiphp_context *acpiphp_grab_context(struct acpi_device *adev) struct acpiphp_context *context; acpi_lock_hp_context(); + context = acpiphp_get_context(adev); - if (!context || context->func.parent->is_going_away) { - acpi_unlock_hp_context(); - return NULL; + if (!context) + goto unlock; + + if (context->func.parent->is_going_away) { + acpiphp_put_context(context); + context = NULL; + goto unlock; } + get_bridge(context->func.parent); acpiphp_put_context(context); + +unlock: acpi_unlock_hp_context(); return context; } -- 2.20.1