io_uring: add IOPOLL and reserved field checks to IORING_OP_UNLINKAT

We can't support IOPOLL with non-pollable request types, and we should
check for unused/reserved fields like we do for other request types.

Fixes: 4aa2c1e08fda ("io_uring: add support for IORING_OP_UNLINKAT")
Cc: stable@vger.kernel.org
Reported-by: Dmitry Kadashev <dkadashev@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 02eda0575c56d92897d00a4ff9a3e3806dff0540..a0bb3cc7d3bb4f870147993b7c57dc1140718eca 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -3514,6 +3514,10 @@ static int io_unlinkat_prep(struct io_kiocb *req,
        struct io_unlink *un = &req->unlink;
        const char __user *fname;
 
+       if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+               return -EINVAL;
+       if (sqe->ioprio || sqe->off || sqe->len || sqe->buf_index)
+               return -EINVAL;
        if (unlikely(req->flags & REQ_F_FIXED_FILE))
                return -EBADF;