[PATCH] ocxl: fix pci device refcount leak when calling get_function_0()

[Yang Yingliang]

As comment of pci_get_domain_bus_and_slot() says, it returns
a pci device with refcount increment, so when finish using it,
pci_dev_put() needs be called.

In get_dvsec_vendor0(), in normal path, the returned pci device
is passed to dev0, so after using dev0 in the callers, it need
be put, in error path, pci_dev_put() also needs be called.

pci_get_domain_bus_and_slot() is called when PCI_FUNC() returns
non-zero, check this before put.

Fixes: 87db7579ebd5 ("ocxl: control via sysfs whether the FPGA is reloaded on a 
link reset")
Signed-off-by: Yang Yingliang <yangyingli...@huawei.com>
---
 drivers/misc/ocxl/config.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/ocxl/config.c b/drivers/misc/ocxl/config.c
index e401a51596b9..4da5a2b8514c 100644
--- a/drivers/misc/ocxl/config.c
+++ b/drivers/misc/ocxl/config.c
@@ -196,16 +196,21 @@ static int read_dvsec_vendor(struct pci_dev *dev)
 static int get_dvsec_vendor0(struct pci_dev *dev, struct pci_dev **dev0,
                             int *out_pos)
 {
+       bool need_put;
        int pos;
 
        if (PCI_FUNC(dev->devfn) != 0) {
                dev = get_function_0(dev);
                if (!dev)
                        return -1;
+               need_put = true;
        }
        pos = find_dvsec(dev, OCXL_DVSEC_VENDOR_ID);
-       if (!pos)
+       if (!pos) {
+               if (need_put)
+                       pci_dev_put(dev);
                return -1;
+       }
        *dev0 = dev;
        *out_pos = pos;
        return 0;
@@ -222,6 +227,8 @@ int ocxl_config_get_reset_reload(struct pci_dev *dev, int 
*val)
 
        pci_read_config_dword(dev0, pos + OCXL_DVSEC_VENDOR_RESET_RELOAD,
                              &reset_reload);
+       if (PCI_FUNC(dev->devfn) != 0)
+               pci_dev_put(dev0);
        *val = !!(reset_reload & BIT(0));
        return 0;
 }
@@ -243,6 +250,8 @@ int ocxl_config_set_reset_reload(struct pci_dev *dev, int 
val)
                reset_reload &= ~BIT(0);
        pci_write_config_dword(dev0, pos + OCXL_DVSEC_VENDOR_RESET_RELOAD,
                               reset_reload);
+       if (PCI_FUNC(dev->devfn) != 0)
+               pci_dev_put(dev0);
        return 0;
 }
 
-- 
2.25.1