CVE-2026-31657 Linux内核batman-adv模块UAF漏洞

/** * Conceptual PoC for CVE-2026-31657 (batman-adv UAF) * This demonstrates the race condition logic. * Note: Actual exploitation requires a specific kernel environment. */ #include <linux/module.h> #include <net/genetlink.h> // Simplified representation of the vulnerable flow void trigger_race_condition() { // Step 1: Reader thread dumps claim via Netlink // batadv_bla_dump_claim() accesses claim->backbone_gw // without holding a reference (rcu_read_lock might be active, but pointer is dying). // Step 2: Writer thread (batadv_bla_add_claim) replaces backbone_gw // and drops the last reference, freeing the memory. // kref_put(&old_gw->refcount, batadv_backbone_gw_release_ref); // Step 3: Reader thread dereferences the freed pointer // access freed memory -> Oops/Exploit } // In a real scenario, this would involve sending specific // B.A.T.M.A.N. packets to trigger the add_claim path // while simultaneously triggering a dump or check.