[PATCH 1/1] PCI: check return value of pci_find_ext_capability

[Pan Bian <bianpan201603@163.com>]

From: Pan Bian <bianpan2016@163.com>

Function pci_find_ext_capability() will returns 0 on failure, and its
return value should be checked before it is used. However, in function
pcie_port_enable_msix(), its return value is not checked. This patch
adds the check.

Signed-off-by: Pan Bian <bianpan2016@163.com>
---
 drivers/pci/pcie/portdrv_core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index cea504f..001951d 100644
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -103,6 +103,8 @@ static int pcie_port_enable_msix(struct pci_dev *dev, int *irqs, int mask)
 		 * interrupt message."
 		 */
 		pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
+		if (!pos)
+			goto out_free_irqs;
 		pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &reg32);
 		entry = reg32 >> 27;
 		if (entry >= nr_entries)
-- 
1.9.1