CVE-2026-43027 Linux内核释放后重用漏洞

/* * PoC Concept for CVE-2026-43027 * This snippet demonstrates the steps to trigger the UAF. * Requires kernel module development context. */ #include <linux/module.h> #include <linux/netfilter.h> #include <net/netfilter/nf_conntrack_helper.h> static struct nf_conntrack_helper *test_helper; static int __init init_poc(void) { // 1. Register a helper (simplified) // test_helper = kzalloc(...); // nf_conntrack_helper_register(test_helper); // 2. Create expectations associated with the helper // (Code to create expectations via nf_ct_expect_add) // 3. Unregister the helper // Bug: nf_conntrack_helper_unregister passes NULL internally, // leaving expectations dangling. // nf_conntrack_helper_unregister(test_helper); // 4. Trigger access to dangling pointer // Reading /proc/net/nf_conntrack_expect causes UAF return 0; } static void __exit exit_poc(void) { // Cleanup } module_init(init_poc); module_exit(exit_poc);