[PATCH] PCIE/PME: fix possible use-after-free on remove

[Sven Van Asbroeck <thesven73@gmail.com>]

In remove(), ensure that the pme work cannot run after kfree()
is called. Otherwise, this could result in a use-after-free.

This issue was detected with the help of Coccinelle.

Cc: Sinan Kaya <okaya@kernel.org>
Cc: Frederick Lawler <fred@fredlawl.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Signed-off-by: Sven Van Asbroeck <TheSven73@gmail.com>
---
 drivers/pci/pcie/pme.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/pcie/pme.c b/drivers/pci/pcie/pme.c
index 0dbcf429089f..87823f669ccc 100644
--- a/drivers/pci/pcie/pme.c
+++ b/drivers/pci/pcie/pme.c
@@ -427,9 +427,12 @@ static int pcie_pme_resume(struct pcie_device *srv)
  */
 static void pcie_pme_remove(struct pcie_device *srv)
 {
+	struct pcie_pme_service_data *data = get_service_data(srv);
+
 	pcie_pme_suspend(srv);
 	free_irq(srv->irq, srv);
-	kfree(get_service_data(srv));
+	cancel_work_sync(&data->work);
+	kfree(data);
 }
 
 static int pcie_pme_runtime_suspend(struct pcie_device *srv)
-- 
2.17.1