From b6a8f349563fbbc6ba315889e645cc1c2adb6a63 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 d44b558..7f2b9ef 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; } -- 2.7.4