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>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
index 5482d4ed8256..c2485542f543 100644
--- 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);