linux-ext4 - [PATCH 03/35] ext4: Fix off-by-in in loop termination in ext4_find_unwritten

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20170601093245.29238-4-jack@suse.cz>
Date:   Thu,  1 Jun 2017 11:32:13 +0200
From:   Jan Kara <jack@...e.cz>
To:     <linux-mm@...ck.org>
Cc:     Hugh Dickins <hughd@...gle.com>,
        David Howells <dhowells@...hat.com>,
        linux-afs@...ts.infradead.org,
        Ryusuke Konishi <konishi.ryusuke@....ntt.co.jp>,
        linux-nilfs@...r.kernel.org, Bob Peterson <rpeterso@...hat.com>,
        cluster-devel@...hat.com, Jaegeuk Kim <jaegeuk@...nel.org>,
        linux-f2fs-devel@...ts.sourceforge.net, tytso@....edu,
        linux-ext4@...r.kernel.org, Ilya Dryomov <idryomov@...il.com>,
        "Yan, Zheng" <zyan@...hat.com>, ceph-devel@...r.kernel.org,
        linux-btrfs@...r.kernel.org, David Sterba <dsterba@...e.com>,
        "Darrick J . Wong" <darrick.wong@...cle.com>,
        linux-xfs@...r.kernel.org,
        Nadia Yvette Chambers <nyc@...omorphy.com>,
        Jan Kara <jack@...e.cz>
Subject: [PATCH 03/35] ext4: Fix off-by-in in loop termination in ext4_find_unwritten_pgoff()

There is an off-by-one error in loop termination conditions in
ext4_find_unwritten_pgoff() since 'end' may index a page beyond end of
desired range if 'endoff' is page aligned. It doesn't have any visible
effects but still it is good to fix it.

Signed-off-by: Jan Kara <jack@...e.cz>
---
 fs/ext4/file.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index bbea2dccd584..2b00bf84c05b 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -474,7 +474,7 @@ static int ext4_find_unwritten_pgoff(struct inode *inode,
 	endoff = (loff_t)end_blk << blkbits;
 
 	index = startoff >> PAGE_SHIFT;
-	end = endoff >> PAGE_SHIFT;
+	end = (endoff - 1) >> PAGE_SHIFT;
 
 	pagevec_init(&pvec, 0);
 	do {
-- 
2.12.3