CVE-2026-31644 Linux内核lan966x驱动释放后利用漏洞

/* * Conceptual PoC for CVE-2026-31644 Logic Flow * This code demonstrates the vulnerable logic flow where resources are freed * before ensuring the new allocation succeeded, leading to UAF. */ #include <stdio.h> #include <stdlib.h> // Simulating kernel structures struct page { int data; }; struct dma_desc { struct page *pg; }; void simulated_vulnerable_function() { struct dma_desc *old_desc = malloc(sizeof(struct dma_desc)); old_desc->pg = malloc(sizeof(struct page)); printf("[+] Step 1: Initialized DMA descriptor and allocated page. "); // Simulate reload attempt struct page *new_page = NULL; // Simulate allocation failure (e.g., memory pressure) if (rand() % 2 == 0) { new_page = NULL; } else { new_page = malloc(sizeof(struct page)); } if (!new_page) { printf("[!] Step 2: Allocation of new page failed."); printf("\n[-] Step 3: Vulnerability - Freeing old page immediately."); free(old_desc->pg); // Equivalent to lan966x_fdma_rx_free_pages old_desc->pg = NULL; // Vulnerability: Hardware (DMA) might still be using old_desc printf("\n[-] Step 4: Restoring DMA using old descriptor (UAF Risk)."); printf("\n[!] Impact: Hardware writes to freed memory -> Kernel Panic/Exploit."); // Cleanup for simulation free(old_desc); } else { printf("[+] Allocation succeeded. Safe swap performed."); free(old_desc->pg); free(old_desc); free(new_page); } } int main() { simulated_vulnerable_function(); return 0; }