• Qian Cai's avatar
    vfio/pci: fix memory leaks of eventfd ctx · b7e24664
    Qian Cai authored
    [ Upstream commit 1518ac27 ]
    
    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: default avatarQian Cai <cai@lca.pw>
    Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
    Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
    b7e24664
vfio_pci.c 44.8 KB