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authorRustam Kovhaev <rkovhaev@gmail.com>2020-09-07 11:55:35 -0700
committerPaolo Bonzini <pbonzini@redhat.com>2020-09-11 13:15:11 -0400
commitf65886606c2d3b562716de030706dfe1bea4ed5e (patch)
tree4b6113de58850a3427ee5d31f80d9fb8ce228e7a
parent0f990222108d214a0924d920e6095b58107d7b59 (diff)
downloadlinux-sh-f65886606c2d3b562716de030706dfe1bea4ed5e.tar.gz
KVM: fix memory leak in kvm_io_bus_unregister_dev()
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>
-rw-r--r--virt/kvm/kvm_main.c21
1 files changed, 12 insertions, 9 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 67cd0b88a6b6..cf88233b819a 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -4332,7 +4332,7 @@ 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);
@@ -4349,17 +4349,20 @@ void kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
new_bus = kmalloc(struct_size(bus, range, bus->dev_count - 1),
GFP_KERNEL_ACCOUNT);
- 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);