[PATCH AUTOSEL for 4.4 047/101] qlcnic: fix unchecked return value

Sasha Levin
2018-03-08T05:34:44Z

From: Pan Bian <bianpan2016@163.com>

[ Upstream commit 91ec701a553cb3de470fd471c6fefe3ad1125455 ]

Function pci_find_ext_capability() may return 0, which is an invalid
address. In function qlcnic_sriov_virtid_fn(), its return value is used
without validation. This may result in invalid memory access bugs. This
patch fixes the bug.

Signed-off-by: Pan Bian <bianpan2016@163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_common.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_common.c b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_common.c
index 7327b729ba2e..ffa6885acfc8 100644
--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_common.c
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_common.c
@@ -127,6 +127,8 @@ static int qlcnic_sriov_virtid_fn(struct qlcnic_adapter *adapter, int vf_id)
return 0;

pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
+ if (!pos)
+ return 0;
pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset);
pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride);

--
2.14.1