linux-kernel - [PATCH] PCI: pciehp_core, fix lock imbalance

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Date:	Sat, 17 Jan 2009 16:23:55 +0100
From:	Jiri Slaby <jirislaby@...il.com>
To:	jbarnes@...tuousgeek.org
Cc:	linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org,
	Jiri Slaby <jirislaby@...il.com>,
	Kristen Carlson Accardi <kristen.c.accardi@...el.com>
Subject: [PATCH] PCI: pciehp_core, fix lock imbalance

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@...il.com>
Cc: Kristen Carlson Accardi <kristen.c.accardi@...el.com>
Cc: Jesse Barnes <jbarnes@...tuousgeek.org>
---
 drivers/pci/hotplug/pciehp_core.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
index 5482d4e..c248554 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);
-- 
1.6.1
caught by stanse
--
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