From 58275258ab7826f8825e9df7232cab848917df60 Mon Sep 17 00:00:00 2001
From: Jens Axboe <jaxboe@fusionio.com>
Date: Fri, 29 Oct 2010 08:10:18 -0600
Subject: [PATCH] block: check for proper length of iov entries in
 blk_rq_map_user_iov()

commit 9284bcf4e335e5f18a8bc7b26461c33ab60d0689 upstream.

Ensure that we pass down properly validated iov segments before
calling into the mapping or copy functions.

Reported-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 block/blk-map.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/block/blk-map.c b/block/blk-map.c
index ade0a08c909..267a57b7709 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -205,6 +205,8 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
 			unaligned = 1;
 			break;
 		}
+		if (!iov[i].iov_len)
+			return -EINVAL;
 	}
 
 	if (unaligned || (q->dma_pad_mask & len) || map_data)
-- 
2.39.2