On Wed, 17 Jun 2020 21:29:54 -0400
Sasha Levin wrote:
> From: Qian Cai
>
> [ Upstream commit 1518ac272e789cae8c555d69951b032a275b7602 ]
>
> Finished a qemu-kvm (-device vfio-pci,host=0001:01:00.0) triggers a few
> memory leaks after a while because vfio_pci_set_ctx_trigger_single()
> calls eventfd_ctx_fdget() without the matching eventfd_ctx_put() later.
> Fix it by calling eventfd_ctx_put() for those memory in
> vfio_pci_release() before vfio_device_release().
>
> unreferenced object 0xebff008981cc2b00 (size 128):
> comm "qemu-kvm", pid 4043, jiffies 4294994816 (age 9796.310s)
> hex dump (first 32 bytes):
> 01 00 00 00 6b 6b 6b 6b 00 00 00 00 ad 4e ad de .N..
> ff ff ff ff 6b 6b 6b 6b ff ff ff ff ff ff ff ff
> backtrace:
> [<917e8f8d>] slab_post_alloc_hook+0x74/0x9c
> [] kmem_cache_alloc_trace+0x2b4/0x3d4
> [<5fcec025>] do_eventfd+0x54/0x1ac
> [<82791a69>] __arm64_sys_eventfd2+0x34/0x44
> [] do_el0_svc+0x128/0x1dc
> [] el0_sync_handler+0xd0/0x268
> [] el0_sync+0x164/0x180
> unreferenced object 0x29ff008981cc4180 (size 128):
> comm "qemu-kvm", pid 4043, jiffies 4294994818 (age 9796.290s)
> hex dump (first 32 bytes):
> 01 00 00 00 6b 6b 6b 6b 00 00 00 00 ad 4e ad de .N..
> ff ff ff ff 6b 6b 6b 6b ff ff ff ff ff ff ff ff
> backtrace:
> [<917e8f8d>] slab_post_alloc_hook+0x74/0x9c
> [] kmem_cache_alloc_trace+0x2b4/0x3d4
> [<5fcec025>] do_eventfd+0x54/0x1ac
> [<82791a69>] __arm64_sys_eventfd2+0x34/0x44
> [] do_el0_svc+0x128/0x1dc
> [] el0_sync_handler+0xd0/0x268
> [] el0_sync+0x164/0x180
>
> Signed-off-by: Qian Cai
> Signed-off-by: Alex Williamson
> Signed-off-by: Sasha Levin
> ---
> drivers/vfio/pci/vfio_pci.c | 4
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
> index 7a82735d5308..ab765770e8dd 100644
> --- a/drivers/vfio/pci/vfio_pci.c
> +++ b/drivers/vfio/pci/vfio_pci.c
> @@ -255,6 +255,10 @@ 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)
> + eventfd_ctx_put(vdev->err_trigger);
> + if (vdev->req_trigger)
> + eventfd_ctx_put(vdev->req_trigger);
> }
>
> mutex_unlock(_lock);
This has a fix pending, I'd suggest not picking it on its own:
https://lore.kernel.org/kvm/20200616085052.sahrunsesjyje...@beryllium.lan/
https://lore.kernel.org/kvm/159234276956.31057.6902954364435481688.st...@gimli.home/
Thanks,
Alex
