CVE-2026-43098 Linux内核NFC驱动空指针解引用漏洞

/* * Conceptual PoC for CVE-2026-43098 * This demonstrates the logic flow causing the NULL pointer dereference. * Requires hardware (Samsung S3FWRN5) to trigger in reality. */ #include <linux/module.h> #include <net/sock.h> // Simulating the vulnerable logic flow void vulnerable_logic_simulation() { struct sk_buff *recv_skb = NULL; int count; // Step 1: Consume bytes into current skb (Assume skb existed) // ... processing logic ... // Step 2: Current frame is delivered, skb is consumed. // recv_skb is now conceptually NULL or stale. // Step 3: Attempt to allocate new skb recv_skb = alloc_skb(1024, GFP_KERNEL); if (!recv_skb) { // VULNERABILITY: Allocation failed, but bytes were already consumed. // The function returns 0, but accounting is broken. return; // recv_skb remains NULL } // Step 4: Next interrupt calls this // skb_put_u8(recv_skb, data); // NULL Pointer Dereference here! } // Fix logic: Allocate before consuming void fixed_logic_simulation() { struct sk_buff *recv_skb = NULL; // Allocate BEFORE consuming bytes if (!recv_skb) { recv_skb = alloc_skb(1024, GFP_KERNEL); if (!recv_skb) { return -ENOMEM; // Return error, don't consume bytes } } // Safe to consume now // skb_put_u8(recv_skb, data); }