From mboxrd@z Thu Jan 1 00:00:00 1970 From: mnipxh Subject: [PATCH] fs/buffer.c: grow_buffers: fix the uncorrect check Date: Sun, 01 Jun 2014 02:12:05 +0800 Message-ID: <538A1B75.5030107@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, yanmin_zhang@linux.intel.com, shuox.liu@intel.com To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org When pgoff_t index is 32bit, sector_t block is 64bit, need check if block number is too big. If block is bigger than (4Gb * PAGE_SIZE), index becomes a wrong value. Commit e5657933863f43cc6bb76a54d659303dafaa9e58 wants to do this. But it gives an uncorrect check. I think block != index << sizebits is correct. And it can detect such issue above. Signed-off-by: xinhui.pan --- fs/buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/buffer.c b/fs/buffer.c index 9ddb9fc..1a674a6 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1081,7 +1081,7 @@ grow_buffers(struct block_device *bdev, sector_t block, int size) * Check for a block which wants to lie outside our maximum possible * pagecache index. (this comparison is done using sector_t types). */ - if (unlikely(index != block >> sizebits)) { + if (unlikely(block != index << sizebits)) { char b[BDEVNAME_SIZE]; printk(KERN_ERR "%s: requested out-of-range block %llu for " -- 1.9.1