From d622b89a2f58613a9c1407b22b02aecdd2187a7c Mon Sep 17 00:00:00 2001 From: Tao Ma Date: Sat, 30 Jan 2010 23:32:19 +0800 Subject: [PATCH] ocfs2: Fix memory overflow in cow_by_page. In ocfs2_duplicate_clusters_by_page, we calculate map_end by shifting page_index. But actually in case we meet with a large offset(say in a i686 box, poff_t is only 32 bits and page_index=2056240), we will overflow. So change the type of page_index to loff_t. Signed-off-by: Tao Ma Signed-off-by: Joel Becker --- fs/ocfs2/refcounttree.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c index 74db2be75dd6..5b64468de0b0 100644 --- a/fs/ocfs2/refcounttree.c +++ b/fs/ocfs2/refcounttree.c @@ -2945,7 +2945,7 @@ static int ocfs2_duplicate_clusters_by_page(handle_t *handle, while (offset < end) { page_index = offset >> PAGE_CACHE_SHIFT; - map_end = (page_index + 1) << PAGE_CACHE_SHIFT; + map_end = ((loff_t)page_index + 1) << PAGE_CACHE_SHIFT; if (map_end > end) map_end = end; @@ -3170,7 +3170,7 @@ static int ocfs2_cow_sync_writeback(struct super_block *sb, while (offset < end) { page_index = offset >> PAGE_CACHE_SHIFT; - map_end = (page_index + 1) << PAGE_CACHE_SHIFT; + map_end = ((loff_t)page_index + 1) << PAGE_CACHE_SHIFT; if (map_end > end) map_end = end; -- 2.30.2