From: Alex Williamson alex.williamson@redhat.com
stable inclusion from linux-4.19.149 commit 41a77298809e7be112f91972d794aa231fbe27aa
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[ Upstream commit 5c5866c593bbd444d0339ede6a8fb5f14ff66d72 ]
The next use of the device will generate an underflow from the stale reference.
Cc: Qian Cai cai@lca.pw Fixes: 1518ac272e78 ("vfio/pci: fix memory leaks of eventfd ctx") Reported-by: Daniel Wagner dwagner@suse.de Reviewed-by: Cornelia Huck cohuck@redhat.com Tested-by: Daniel Wagner dwagner@suse.de Signed-off-by: Alex Williamson alex.williamson@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/vfio/pci/vfio_pci.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 86cd8bdfa9f2..94fad366312f 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -409,10 +409,14 @@ static void vfio_pci_release(void *device_data) if (!(--vdev->refcnt)) { vfio_spapr_pci_eeh_release(vdev->pdev); vfio_pci_disable(vdev); - if (vdev->err_trigger) + if (vdev->err_trigger) { eventfd_ctx_put(vdev->err_trigger); - if (vdev->req_trigger) + vdev->err_trigger = NULL; + } + if (vdev->req_trigger) { eventfd_ctx_put(vdev->req_trigger); + vdev->req_trigger = NULL; + } }
mutex_unlock(&driver_lock);