Messages in this thread | | | Date | Thu, 18 Jun 2020 10:29:43 -0400 | From | Sasha Levin <> | Subject | Re: [PATCH AUTOSEL 5.7 280/388] vfio/pci: fix memory leaks of eventfd ctx |
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On Wed, Jun 17, 2020 at 07:25:01PM -0600, Alex Williamson wrote: >On Wed, 17 Jun 2020 21:06:17 -0400 >Sasha Levin <sashal@kernel.org> wrote: > >> From: Qian Cai <cai@lca.pw> >> >> [ 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 ....kkkk.....N.. >> ff ff ff ff 6b 6b 6b 6b ff ff ff ff ff ff ff ff ....kkkk........ >> backtrace: >> [<00000000917e8f8d>] slab_post_alloc_hook+0x74/0x9c >> [<00000000df0f2aa2>] kmem_cache_alloc_trace+0x2b4/0x3d4 >> [<000000005fcec025>] do_eventfd+0x54/0x1ac >> [<0000000082791a69>] __arm64_sys_eventfd2+0x34/0x44 >> [<00000000b819758c>] do_el0_svc+0x128/0x1dc >> [<00000000b244e810>] el0_sync_handler+0xd0/0x268 >> [<00000000d495ef94>] 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 ....kkkk.....N.. >> ff ff ff ff 6b 6b 6b 6b ff ff ff ff ff ff ff ff ....kkkk........ >> backtrace: >> [<00000000917e8f8d>] slab_post_alloc_hook+0x74/0x9c >> [<00000000df0f2aa2>] kmem_cache_alloc_trace+0x2b4/0x3d4 >> [<000000005fcec025>] do_eventfd+0x54/0x1ac >> [<0000000082791a69>] __arm64_sys_eventfd2+0x34/0x44 >> [<00000000b819758c>] do_el0_svc+0x128/0x1dc >> [<00000000b244e810>] el0_sync_handler+0xd0/0x268 >> [<00000000d495ef94>] el0_sync+0x164/0x180 >> >> Signed-off-by: Qian Cai <cai@lca.pw> >> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> >> Signed-off-by: Sasha Levin <sashal@kernel.org> >> --- >> 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 6c6b37b5c04e..080e6608f297 100644 >> --- a/drivers/vfio/pci/vfio_pci.c >> +++ b/drivers/vfio/pci/vfio_pci.c >> @@ -519,6 +519,10 @@ static void vfio_pci_release(void *device_data) >> vfio_pci_vf_token_user_add(vdev, -1); >> 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(&vdev->reflck->lock); > > >This has a fix pending, I'd suggest not picking it on its own: > >https://lore.kernel.org/kvm/20200616085052.sahrunsesjyjeyf2@beryllium.lan/ >https://lore.kernel.org/kvm/159234276956.31057.6902954364435481688.stgit@gimli.home/
Thanks! I'll hold off on this until the fix is in too.
-- Thanks, Sasha
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