From 794e64d5e9c7f088378e093a48eb36a30091d82d Mon Sep 17 00:00:00 2001
From: Neil Brown <neilb@suse.de>
Date: Mon, 10 Dec 2007 15:49:30 -0800
Subject: [PATCH] Fix NULL dereference in umem.c

Fix NULL dereference in umem.c

Signed-off-by: Neil Brown <neilb@suse.de>
Tested-by: Dave Chinner <dgc@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 drivers/block/umem.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/block/umem.c b/drivers/block/umem.c
index 99806f9ee4ce..5f5095afb06b 100644
--- a/drivers/block/umem.c
+++ b/drivers/block/umem.c
@@ -484,7 +484,8 @@ static void process_page(unsigned long data)
 		page->idx++;
 		if (page->idx >= bio->bi_vcnt) {
 			page->bio = bio->bi_next;
-			page->idx = page->bio->bi_idx;
+			if (page->bio)
+				page->idx = page->bio->bi_idx;
 		}
 
 		pci_unmap_page(card->dev, desc->data_dma_handle,
-- 
2.20.1