From: Dexuan Cui decui@microsoft.com
commit 05f151a73ec2b23ffbff706e5203e729a995cdc2 upstream.
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 pci_devices_present_work().
Fixes: 4daace0d8ce8 ("PCI: hv: Add paravirtual PCI front-end for Microsoft Hyper-V VMs") Signed-off-by: Dexuan Cui decui@microsoft.com [lorenzo.pieralisi@arm.com: commit log rework] Signed-off-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com Reviewed-by: Stephen Hemminger stephen@networkplumber.org Reviewed-by: Michael Kelley mikelley@microsoft.com Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/pci/controller/pci-hyperv.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/drivers/pci/controller/pci-hyperv.c +++ b/drivers/pci/controller/pci-hyperv.c @@ -1905,6 +1905,9 @@ static void hv_eject_device_work(struct sizeof(*ejct_pkt), (unsigned long)&ctxt.pkt, VM_PKT_DATA_INBAND, 0);
+ /* For the get_pcichild() in hv_pci_eject_device() */ + put_pcichild(hpdev); + /* For the two refs got in new_pcichild_device() */ put_pcichild(hpdev); put_pcichild(hpdev); put_hvpcibus(hpdev->hbus);