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| author | Rustam Kovhaev <rkovhaev@gmail.com> | 2020-09-07 11:55:35 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-09-26 18:01:28 +0200 |
| commit | 19184bd06f488af62924ff1747614a8cb284ad63 (patch) | |
| tree | 3cc2d22625c32a7adcfdd07773b57e2eef04245e /virt | |
| parent | b59a23d596807a5aa88d8dd5655a66c6843729b3 (diff) | |
| download | linux-stable-19184bd06f488af62924ff1747614a8cb284ad63.tar.gz linux-stable-19184bd06f488af62924ff1747614a8cb284ad63.tar.bz2 linux-stable-19184bd06f488af62924ff1747614a8cb284ad63.zip | |
KVM: fix memory leak in kvm_io_bus_unregister_dev()
[ Upstream commit f65886606c2d3b562716de030706dfe1bea4ed5e ]
when kmalloc() fails in kvm_io_bus_unregister_dev(), before removing
the bus, we should iterate over all other devices linked to it and call
kvm_iodevice_destructor() for them
Fixes: 90db10434b16 ("KVM: kvm_io_bus_unregister_dev() should never fail")
Cc: stable@vger.kernel.org
Reported-and-tested-by: syzbot+f196caa45793d6374707@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=f196caa45793d6374707
Signed-off-by: Rustam Kovhaev <rkovhaev@gmail.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200907185535.233114-1-rkovhaev@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/kvm_main.c | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 2155b52b17ec..6bd01d12df2e 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -3844,7 +3844,7 @@ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, void kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, struct kvm_io_device *dev) { - int i; + int i, j; struct kvm_io_bus *new_bus, *bus; bus = kvm_get_bus(kvm, bus_idx); @@ -3861,17 +3861,20 @@ void kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, new_bus = kmalloc(sizeof(*bus) + ((bus->dev_count - 1) * sizeof(struct kvm_io_range)), GFP_KERNEL); - if (!new_bus) { + if (new_bus) { + memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range)); + new_bus->dev_count--; + memcpy(new_bus->range + i, bus->range + i + 1, + (new_bus->dev_count - i) * sizeof(struct kvm_io_range)); + } else { pr_err("kvm: failed to shrink bus, removing it completely\n"); - goto broken; + for (j = 0; j < bus->dev_count; j++) { + if (j == i) + continue; + kvm_iodevice_destructor(bus->range[j].dev); + } } - memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range)); - new_bus->dev_count--; - memcpy(new_bus->range + i, bus->range + i + 1, - (new_bus->dev_count - i) * sizeof(struct kvm_io_range)); - -broken: rcu_assign_pointer(kvm->buses[bus_idx], new_bus); synchronize_srcu_expedited(&kvm->srcu); kfree(bus); |