After CPR transfer, source QEMU close kvm fd and free kvm_state, "query-balloon" will check kvm_state->sync_mmu and trigger NULL pointer reference.
Signed-off-by: Zhenzhong Duan <[email protected]> --- accel/kvm/kvm-all.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index 9060599cd7..a3e2d11763 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -3479,7 +3479,7 @@ int kvm_device_access(int fd, int group, uint64_t attr, bool kvm_has_sync_mmu(void) { - return kvm_state->sync_mmu; + return kvm_state && kvm_state->sync_mmu; } int kvm_has_vcpu_events(void) -- 2.47.1
