| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.14 03/63] PCI: hv: Fix a memory leak in hv_eject_device_work() | Date | Mon, 20 May 2019 14:13:42 +0200 |
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[ 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 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: Sasha Levin <sashal@kernel.org> --- 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) VM_PKT_DATA_INBAND, 0); put_pcichild(hpdev, hv_pcidev_ref_childlist); + put_pcichild(hpdev, hv_pcidev_ref_initial); put_pcichild(hpdev, hv_pcidev_ref_pnp); put_hvpcibus(hpdev->hbus); } -- 2.20.1
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