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Subject[PATCH 4.14 03/63] PCI: hv: Fix a memory leak in hv_eject_device_work()
[ Upstream commit 05f151a73ec2b23ffbff706e5203e729a995cdc2 ]

When a device is created in new_pcichild_device(), hpdev->refs is set
to 2 (i.e. the initial value of 1 plus the get_pcichild()).

When we hot remove the device from the host, in a Linux VM we first call
hv_pci_eject_device(), which increases hpdev->refs by get_pcichild() and
then schedules a work of hv_eject_device_work(), so hpdev->refs becomes
3 (let's ignore the paired get/put_pcichild() in other places). But in
hv_eject_device_work(), currently we only call put_pcichild() twice,
meaning the 'hpdev' struct can't be freed in put_pcichild().

Add one put_pcichild() to fix the memory leak.

The device can also be removed when we run "rmmod pci-hyperv". On this
path (hv_pci_remove() -> hv_pci_bus_exit() -> hv_pci_devices_present()),
hpdev->refs is 2, and we do correctly call put_pcichild() twice in

Fixes: 4daace0d8ce8 ("PCI: hv: Add paravirtual PCI front-end for Microsoft Hyper-V VMs")
Signed-off-by: Dexuan Cui <>
[ commit log rework]
Signed-off-by: Lorenzo Pieralisi <>
Reviewed-by: Stephen Hemminger <>
Reviewed-by: Michael Kelley <>
Signed-off-by: Sasha Levin <>
drivers/pci/host/pci-hyperv.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index 53d1c08cef4dc..292450c7da625 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -1941,6 +1941,7 @@ static void hv_eject_device_work(struct work_struct *work)

put_pcichild(hpdev, hv_pcidev_ref_childlist);
+ put_pcichild(hpdev, hv_pcidev_ref_initial);
put_pcichild(hpdev, hv_pcidev_ref_pnp);

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