Actually, no, this is the fix:

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 7006b5b2106d..be2fc5793ddd 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -537,7 +537,7 @@ static size_t push_pipe(struct iov_iter *i, size_t size,
 		buf->ops = &default_pipe_buf_ops;
 		buf->page = page;
 		buf->offset = 0;
-		buf->len = max_t(ssize_t, left, PAGE_SIZE);
+		buf->len = min_t(ssize_t, left, PAGE_SIZE);
 		left -= buf->len;
 		iter_head++;
 		pipe->head = iter_head;

David