[PATCH 6/8] PCI: iproc: fix a leaked reference by adding missing of_node_put

Wen Yang
2019-02-27T04:40:41Z

The call to of_parse_phandle returns a node pointer with refcount
incremented thus it must be explicitly decremented after the last
usage.
iproc_msi_init also calls of_node_get to increase refcount
(proc_msi_init -> iproc_msi_alloc_domains -> pci_msi_create_irq_domain
-> msi_create_irq_domain -> irq_domain_create_linear -> __irq_domain_add),
so irq_domain will not be affected when it is released.

Detected by coccinelle with the following warnings:
./drivers/pci/controller/pcie-iproc.c:1323:3-9: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 1299, but without a corresponding object release within this function.
./drivers/pci/controller/pcie-iproc.c:1330:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 1299, but without a corresponding object release within this function.

Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: linux-pci@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
---
drivers/pci/controller/pcie-iproc.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/pcie-iproc.c b/drivers/pci/controller/pcie-iproc.c
index c20fd6b..9998c5c 100644
--- a/drivers/pci/controller/pcie-iproc.c
+++ b/drivers/pci/controller/pcie-iproc.c
@@ -1320,14 +1320,18 @@ static int iproc_pcie_msi_enable(struct iproc_pcie *pcie)
if (pcie->need_msi_steer) {
ret = iproc_pcie_msi_steer(pcie, msi_node);
if (ret)
- return ret;
+ goto out_put_node;
}

/*
* If another MSI controller is being used, the call below should fail
* but that is okay
*/
- return iproc_msi_init(pcie, msi_node);
+ ret = iproc_msi_init(pcie, msi_node);
+
+out_put_node:
+ of_node_put(msi_node);
+ return ret;
}

static void iproc_pcie_msi_disable(struct iproc_pcie *pcie)
--
2.9.5