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authorDexuan Cui <decui@microsoft.com>2019-03-04 21:34:48 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-05-16 19:40:30 +0200
commitd3a9cd23b172d1a873c05fb9d904538e58090f8b (patch)
parent7f9572e798ea8c7a6a7b846c8fb577905e3d4a6c (diff)
PCI: hv: Fix a memory leak in hv_eject_device_work()
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>
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index 9ba4d12c179c..5b54d36077a9 100644
--- 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 work_struct *work)
sizeof(*ejct_pkt), (unsigned long)&ctxt.pkt,
+ /* For the get_pcichild() in hv_pci_eject_device() */
+ put_pcichild(hpdev);
+ /* For the two refs got in new_pcichild_device() */