From 8112006f41fd76ddf4988f8ddd904563db85613c Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sun, 16 Jun 2013 00:38:30 +0200 Subject: [PATCH] ACPI / dock: Take ACPI scan lock in write_undock() Since commit 3757b94 (ACPI / hotplug: Fix concurrency issues and memory leaks) acpi_bus_scan() and acpi_bus_trim() must always be called under acpi_scan_lock, but currently the following scenario violating that requirement is possible: write_undock() handle_eject_request() hotplug_dock_devices() dock_remove_acpi_device() acpi_bus_trim() Fix that by making write_undock() acquire acpi_scan_lock before calling handle_eject_request() as appropriate (begin_undock() is under the lock too in analogy with acpi_dock_deferred_cb()). Signed-off-by: Rafael J. Wysocki Cc: 3.9+ Acked-by: Toshi Kani --- drivers/acpi/dock.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c index 4fdea381ef21..ec117c6c996c 100644 --- a/drivers/acpi/dock.c +++ b/drivers/acpi/dock.c @@ -868,8 +868,10 @@ static ssize_t write_undock(struct device *dev, struct device_attribute *attr, if (!count) return -EINVAL; + acpi_scan_lock_acquire(); begin_undock(dock_station); ret = handle_eject_request(dock_station, ACPI_NOTIFY_EJECT_REQUEST); + acpi_scan_lock_release(); return ret ? ret: count; } static DEVICE_ATTR(undock, S_IWUSR, NULL, write_undock); -- 2.20.1