From 4f936f0cd8b8d294bd1dcc7b7b1810b2c886452d Mon Sep 17 00:00:00 2001
From: Thomas Schoebel-Theuer <tst@schoebel-theuer.de>
Date: Tue, 2 Dec 2014 12:23:45 +0100
Subject: [PATCH] bio: fix invalid block allocations

---
 kernel/mars_bio.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/mars_bio.c b/kernel/mars_bio.c
index dde4732d..87641dc7 100644
--- a/kernel/mars_bio.c
+++ b/kernel/mars_bio.c
@@ -294,6 +294,9 @@ static int bio_ref_get(struct bio_output *output, struct mref_object *mref)
 
 
 	if (!mref->ref_data) { // buffered IO.
+		if (unlikely(mref->ref_len <= 0)) {
+			goto done;
+		}
 		status = -ENOMEM;
 		mref->ref_data = brick_block_alloc(mref->ref_pos, (mref_a->alloc_len = mref->ref_len));
 		if (unlikely(!mref->ref_data)) {