CVE-2026-43249: Linux内核9p/xen双重释放漏洞

/* * Conceptual PoC for Race Condition in xen_9pfs_front_free * This simulates the concurrency issue leading to Double Free. */ #include <linux/mutex.h> // Vulnerable structure representation struct xen_9pfs_front_priv { struct list_head list; // ... other fields ... }; // Simulated vulnerable function (Before Fix) void vulnerable_xen_9pfs_front_free(struct xen_9pfs_front_priv *priv) { // Vulnerability: No lock here list_del(&priv->list); kfree(priv); // First free // If another thread enters here, it will kfree again -> Double Free } // Attacker scenario: // Thread A: calls vulnerable_xen_9pfs_front_free(priv) // Thread B: calls vulnerable_xen_9pfs_front_free(priv) concurrently // Result: Kernel Panic (General Protection Fault)