PCI: fix reference leak in pci_get_dev_by_id()

Alex Chiang and Matthew Wilcox pointed out that pci_get_dev_by_id() does
not properly decrement the reference on the from pointer if it is
present, like the documentation for the function states it will.

It fixes a pretty bad leak in the hotplug core (we were leaking an
entire struct pci_dev for each function of each offlined card, the first
time around; subsequent onlines/offlines were ok).

Cc: Matthew Wilcox <matthew@wil.cx>
Cc: stable <stable@kernel.org>
Tested-by: Alex Chiang <achiang@hp.com>
Acked-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/pci/search.c b/drivers/pci/search.c
index 217814fef4ef..3b3b5f178797 100644
--- a/drivers/pci/search.c
+++ b/drivers/pci/search.c
@@ -280,6 +280,8 @@ static struct pci_dev *pci_get_dev_by_id(const struct pci_device_id *id,
                               match_pci_dev_by_id);
         if (dev)
                 pdev = to_pci_dev(dev);
+        if (from)
+                pci_dev_put(from);
         return pdev;
 }