CVE-2026-31743: Linux内核zynqmp_nvmem内存损坏漏洞

/* * PoC Concept for CVE-2026-31743 * Demonstrating the logic error in buffer size handling within zynqmp_nvmem * This code simulates the vulnerability condition where a smaller buffer * is allocated/copied into than what is required. */ #include <stdio.h> #include <string.h> #include <stdlib.h> #define EXPECTED_DATA_SIZE 64 #define INCORRECT_BUFFER_SIZE 32 // The bug: using wrong size void simulate_vulnerable_nvmem_ops() { char *dma_buffer; char source_data[EXPECTED_DATA_SIZE]; // Initialize source data with a pattern memset(source_data, 0x41, EXPECTED_DATA_SIZE); // Vulnerability: Allocating buffer with incorrect (smaller) size dma_buffer = (char *)malloc(INCORRECT_BUFFER_SIZE); if (!dma_buffer) { perror("malloc failed"); return; } printf("[+] Allocated DMA buffer of size: %d\n", INCORRECT_BUFFER_SIZE); printf("[+] Attempting to copy data of size: %d\n", EXPECTED_DATA_SIZE); // Vulnerability: memcpy uses the larger size, causing overflow // In the actual driver, this leads to kernel memory corruption. memcpy(dma_buffer, source_data, EXPECTED_DATA_SIZE); printf("[-] Memory corruption occurred due to buffer size mismatch.\n"); free(dma_buffer); } int main() { simulate_vulnerable_nvmem_ops(); return 0; }