PCI hotplug: fix lock imbalance in pciehp

set_lock_status omits mutex_unlock in fail path. Add the omitted
unlock.

As a result a lockup caused by this can be triggered from userspace
by writing 1 to /sys/bus/pci/slots/.../lock often enough.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
index 5482d4e..c248554 100644 (file)
--- a/drivers/pci/hotplug/pciehp_core.c
+++ b/drivers/pci/hotplug/pciehp_core.c
@@ -126,8 +126,10 @@ static int set_lock_status(struct hotplug_slot *hotplug_slot, u8 status)
        mutex_lock(&slot->ctrl->crit_sect);
 
        /* has it been >1 sec since our last toggle? */
-       if ((get_seconds() - slot->last_emi_toggle) < 1)
+       if ((get_seconds() - slot->last_emi_toggle) < 1) {
+               mutex_unlock(&slot->ctrl->crit_sect);
                return -EINVAL;
+       }
 
        /* see what our current state is */
        retval = get_lock_status(hotplug_slot, &value);