linux-kernel - [PATCH 3.2 052/106] ext4: fix fdatasync(2) after extent manipulation operations

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]

Date:   Sat, 09 Sep 2017 22:47:39 +0100
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org, "Theodore Ts'o" <tytso@....edu>,
        "Jan Kara" <jack@...e.cz>
Subject: [PATCH 3.2 052/106] ext4: fix fdatasync(2) after extent
 manipulation operations

3.2.93-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Jan Kara <jack@...e.cz>

commit 67a7d5f561f469ad2fa5154d2888258ab8e6df7c upstream.

Currently, extent manipulation operations such as hole punch, range
zeroing, or extent shifting do not record the fact that file data has
changed and thus fdatasync(2) has a work to do. As a result if we crash
e.g. after a punch hole and fdatasync, user can still possibly see the
punched out data after journal replay. Test generic/392 fails due to
these problems.

Fix the problem by properly marking that file data has changed in these
operations.

Fixes: a4bb6b64e39abc0e41ca077725f2a72c868e7622
Signed-off-by: Jan Kara <jack@...e.cz>
Signed-off-by: Theodore Ts'o <tytso@....edu>
[bwh: Backported to 3.2: Only the punch-hole operation is supported, and
 it's in extents.c.]
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -5023,6 +5023,8 @@ out:
 	ext4_orphan_del(handle, inode);
 	inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
 	ext4_mark_inode_dirty(handle, inode);
+	if (err >= 0)
+		ext4_update_inode_fsync_trans(handle, inode, 1);
 	ext4_journal_stop(handle);
 	return err;
 }